U.S. patent number 8,257,257 [Application Number 11/714,495] was granted by the patent office on 2012-09-04 for capsule type medical device.
This patent grant is currently assigned to Olympus Corporation. Invention is credited to Masatoshi Homan, Hironao Kawano, Hironobu Takizawa, Akio Uchiyama, Takeshi Yokoi.
United States Patent |
8,257,257 |
Takizawa , et al. |
September 4, 2012 |
Capsule type medical device
Abstract
A capsule type medical device is of a type of a capsule type
medical device that is introduced inside the living body to gather
in-vivo information, and comprises a capsule shaped casing; an
in-vivo information acquisition device for acquiring the in-vivo
information; a communication device for sending the in-vivo
information acquired by the in-vivo information acquisition device
to outside of the living body by wireless; at least one pair of
first electrodes provided in a vicinity of one end along an axis of
the casing for giving electric stimulation to body tissue in the
living body; a first current control device for sending current to
the first electrodes; and an interelectrode distance variation
device for changing a distance between the electrodes.
Inventors: |
Takizawa; Hironobu (Tokyo,
JP), Uchiyama; Akio (Yokohama, JP), Kawano;
Hironao (Tokyo, JP), Yokoi; Takeshi (Tokyo,
JP), Homan; Masatoshi (Tokyo, JP) |
Assignee: |
Olympus Corporation (Tokyo,
JP)
|
Family
ID: |
35432358 |
Appl.
No.: |
11/714,495 |
Filed: |
March 6, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070161851 A1 |
Jul 12, 2007 |
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Current U.S.
Class: |
600/302; 600/103;
600/101 |
Current CPC
Class: |
A61B
1/041 (20130101); A61B 1/31 (20130101); A61B
1/00156 (20130101); A61B 5/6886 (20130101); A61B
34/73 (20160201) |
Current International
Class: |
A61B
5/07 (20060101) |
Field of
Search: |
;600/101-104,116,300,302
;607/40 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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07-289504 |
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Nov 1995 |
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JP |
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H11-225984 |
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Aug 1999 |
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JP |
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2003-135388 |
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May 2003 |
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JP |
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2003-210393 |
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Jul 2003 |
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JP |
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2003-284784 |
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Oct 2003 |
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JP |
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2003-299613 |
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Oct 2003 |
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JP |
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2004-049756 |
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Feb 2004 |
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JP |
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2005-185644 |
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Jul 2005 |
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JP |
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2007-521938 |
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Aug 2007 |
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JP |
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01/08548 |
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Feb 2001 |
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WO |
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01/08549 |
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Feb 2001 |
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WO |
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WO 03/001966 |
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Jan 2003 |
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WO |
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2004/066903 |
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Aug 2004 |
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WO |
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WO 2005/082248 |
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Sep 2005 |
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WO |
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WO 2007/007648 |
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Jan 2007 |
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WO |
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Other References
Japanese Official Action dated Jun. 15, 2010 together with an
English language translation. cited by other .
Japanese Office Action dated Aug. 24, 2010 with English
translation. cited by other .
Japanese Office Action (Notice of Allowance) dated Nov. 16, 2010.
cited by other.
|
Primary Examiner: Kahelin; Michael
Assistant Examiner: D'Angelo; Michael
Attorney, Agent or Firm: Scully, Scott, Murphy &
Presser, P.C.
Claims
The invention claimed is:
1. A capsule type medical device that is adapted to be introduced
inside a living body to gather in-vivo information, comprising: a
capsule shaped casing adapted for use in the gastrointestinal
tract; an in-vivo information acquisition device for acquiring the
in-vivo information; a communication device for sending the in-vivo
information which is acquired by the in-vivo information
acquisition device to outside of the living body by wireless; at
least one pair of first electrodes which are provided in a vicinity
of one end along an axis of the casing, for giving electric
stimulation to a body tissue inside a lumen of the gastrointestinal
tract to propel the capsule shaped casing within the
gastrointestinal tract; a first current control device for sending
current to the first electrodes; and a first interelectrode
distance variation device for changing a distance between the first
electrodes, wherein the first interelectrode distance variation
device is formed by flexible wires which support the first
electrodes at tip ends, and the flexible wires are supported by the
casing at base ends thereof and protrude externally from the
casing.
2. The capsule type medical device according to claim 1, wherein
the flexible wires are in a belt shape with a width of the first
electrodes being substantially the same as that of the flexible
wires.
3. The capsule type medical device according to claim 1, wherein
the flexible wires comprise conductive wire members for sending
current from the base ends to the tip ends and insulating covering
members for insulating and covering the conductive wire members,
and at least one of the conductive members and the insulation
covering members have flexibility and elasticity.
4. The capsule type medical device according to claim 1, wherein
the flexible wires are made of superelastic alloy and/or
superelastic polymer material.
5. The capsule type medical device according to claim 1, further
comprising a wire bundling device for bundling the flexible wires
in a vicinity of the tip end, wherein the wire bundling device
dissolves inside the living body.
Description
TECHNICAL FIELD
The present invention relates to a capsule medical device that
observes the living body, and in particular, a device that moves
inside the living body by giving electric stimulation to body
tissue, making it possible to observe desired positions.
Priority is claimed on Japanese Patent Application No. 2004-261015,
filed Sep. 8, 2004, and on Japanese Patent Application No.
2004-296178, filed Oct. 8, 2004, the contents of which are
incorporated herein by reference.
BACKGROUND ART OF THE INVENTION
For a method of checking the health condition of a person being
examined, such methods as medical check or examination by means of
an endoscope are widely known. Moreover, an examination method that
uses a capsule type medical device wherein an examination
instrument formed in capsule shape is introduced inside the living
body to conduct easy physical condition examination is known (for
example, refer Japanese Unexamined Patent Application, First
Publication No. 2003-135388). Various types of capsule medical
devices similar to the aforementioned device are available, one of
which is an electric propelling type device wherein local electric
stimulation is given to body tissue through electrodes and
contraction of the body tissue is utilized to move inside the
living body (for example, refer to PCT International Publication
No. WO 01/08548, and U.S. Patent Application Publication No.
2003/0125788).
Normally, a capsule medical device, when introduced to the living
body, moves naturally inside the digestive tube through peristaltic
movement of a luminal organ such as the small intestine. However,
this electric propelling type capsule medical device promotes
forward movement or movement in a reverse direction by giving
electric stimulation locally to body tissue such as a luminal
organ, inducing contraction motion (inducing compulsory peristalsis
or local muscle contraction) different from peristaltic movement
which is natural (autonomic) to the body tissue. This allows speedy
reaching to position to be observed, or detailed observation at one
location. Hence, an effective observation is achieved.
In the capsule type medical device disclosed in PCT International
Publication No. WO 01/08548, electrodes are provided in an
expandable balloon in order to cope with changes in the diameter of
a luminal organ. However, in this device, it is necessary to expand
the balloon by blowing a fluid such as air into the capsule type
medical device from outside of the living body using a tube or the
like. Hence, a relatively large tube is needed to blow the fluid
into the balloon, making it difficult to deploy the device inside
the living body. Moreover, often the person examined feels uneasy
or uncomfortable. Furthermore, if the tube gets caught inside the
luminal organ, stable propelling of the capsule medical device may
be interrupted. Moreover, in the capsule type medical device
disclosed in PCT International Publication No. WO 01/08548, a
detailed description concerning the structure and mechanisms behind
the power supply to the electrode are not given, and it is clear
that a further improvement is needed.
In the capsule type medical device disclosed in the specification
of U.S. Patent Application Publication 2003/0125788, electrodes for
electric stimulation are attached to swingable flap, and by opening
the flap with expandable balloon, the problem of change in the
diameter of the luminal organ is handled. However, similar to the
model disclosed in Japanese Unexamined Patent Application, First
Publication No. 2003-135388, a tube is needed to blow air or the
like to expand the balloon. In addition, even when the flap is
opened to the maximum size, the distance between the electrodes is
about the same as the diameter of the capsule, hence, a problem
occurs in that the device clearly cannot be used for luminal organs
with a diameter larger than that of the capsule.
DISCLOSURE OF THE INVENTION
A capsule type medical device of the present invention is a capsule
type medical device that is introduced inside a living body to
gather in-vivo information, including: a capsule shaped casing; an
in-vivo information acquisition device for acquiring the in-vivo
information; a communication device for sending the in-vivo
information which is acquired by the in-vivo information
acquisition device to outside of the living body by wireless; at
least one pair of first electrodes which are provided in a vicinity
of one end along an axis of the casing, for giving electric
stimulation to a body tissue in the living body; a first current
control device for sending current to the first electrodes; and a
first interelectrode distance variation device for changing a
distance between the first electrodes.
According to the capsule type medical device of the present
invention, since the capsule type medical device has an
interelectrode distance variation device, the electrodes are
accurately made to contact body tissue and give electric
stimulation. Hence, contraction movement of the body tissue is
accurately achieved, which enables stable propelling of the capsule
type medical device.
In the capsule type medical device of the present invention, it is
preferable that a maximum distance between the first electrodes
which may be changed by the first interelectrode distance variation
device be set to at least double an outer diameter of the
casing.
According to the capsule type medical device of the present
invention, the electrodes are accurately made to contact the
luminal organ due to the diameter clearly larger than that of the
casing.
It is preferable that the capsule type medical device of the
present invention further include, at least one pair of second
electrodes, which are provided in a vicinity of another end along
the axis of the casing and in a location not coinciding with the
in-vivo information acquisition device, for giving electric
stimulation to the body tissue; a second current control device for
sending current to the second electrodes; and a second
interelectrode distance variation device for changing a distance
between the second electrodes.
According to the capsule type medical device of the present
invention, the current sent to the first electrodes and the second
electrodes may be controlled independently of each other, hence,
the capsule type medical device may freely be moved forward and
backward. In other words, it moves forward due to electric
stimulation given to the body tissue through the first electrodes
that are provided on one edge side of the casing. Likewise, it
moves backward due to electric stimulation given to the body tissue
through the second electrodes that are provided on the other edge
side of the casing.
In the capsule type medical device of the present invention, it is
preferable that the first interelectrode distance variation device
be formed by flexible wires which support the first electrodes at
tip ends, and the flexible wires be supported by the casing at base
ends thereof and protrude externally from the casing.
According to the capsule type medical device of the present
invention, contact between the electrodes and the body tissue may
be made more accurate through elastic deformation of the flexible
wire. Moreover, when the device is introduced inside the lumenal
organ, change in the diameter of the lumenal organ is accurately
compensated for and constant contact between the electrodes and the
body tissue is assured.
In the capsule type medical device of the present invention, it is
preferable that the flexible wires be in a belt shape with a width
of the first electrodes being substantially the same as that of the
flexible wires.
According to the capsule type medical device of the present
invention, a larger area for electric contact with the body tissue
is secured, hence, the amount of electric current necessary for
contraction is sent to the body tissue in a stable manner.
In the capsule medical device of the present invention, it is
preferable that the flexible wires comprise conductive wire members
for sending current from the base ends to the tip ends and
insulating covering members for insulating and covering the
conductive wire members, and at least one of the conductive members
and the insulation covering members have flexibility and
elasticity.
According to the capsule type medical device of the present
invention, the conductive wire member is covered and insulated with
insulation covering material, hence, short circuit between flexible
wires is accurately prevented, enabling arrangement of flexible
wires near each other.
In the capsule medical device of the present invention, it is
preferable that the flexible wires be made of superelastic alloy
and/or superelastic polymer material.
According to the capsule type medical device of the present
invention, large elastic deformation of the flexible wire is
achieved, change in the diameter of the lumenal organ inside the
living body is accurately compensated for and constant contact
between the electrodes and the body tissue is assured.
It is preferable that the capsule type medical device of the
present invention further include a wire bundling device for
bundling the flexible wires in a vicinity of the tip end, and the
wire bundling device dissolves inside the living body.
According to the capsule type medical device of the present
invention, when the flexible wire is bundled at the tip end side,
enables easy introduction of a capsule type medical device into the
living body because the flexible wire and electrode do not become
obstacles when the capsule type medical device is placed in the
living body, for example, through swallowing of the capsule type
medical device. After deployment of the capsule type medical
device, the wire bundling device are dissolved by stomach acid or
the like, hence, the wires are unbundled, enabling alteration of
the interelectrode distance.
In the capsule type medical device of the present invention, it is
preferable that the first interelectrode distance variation device
be an outer shell unit which is movably attached to the casing to
the outward direction, and the first electrodes be fixed on the
outer shell unit.
According to the capsule type medical device of the present
invention, a plurality of electrodes are anchored in the outer
shell unit to form one unit, and by moving the electrodes along the
radial direction of the outer shell unit, the electrodes are
accurately made to contact the body tissue.
In the capsule type medical device of the present invention, it is
preferable that the first electrodes be provided in a number of two
or more along a periphery of the casing, and the capsule type
medical device further comprise an electrode selector for selecting
electrodes among the first electrodes to send current to from the
current control device.
According to the capsule type medical device of the present
invention, selection of positions to give electric stimulation
along the periphery enables accurate movement of the capsule type
medical device in a horizontal direction as well.
In the capsule type medical device of the present invention, it is
preferable that the electrode selector be an electrode size
variation device which changes a size of each first electrode that
gives electric stimulation to the body tissue, by selecting some
electrodes arbitrarily among the first electrodes.
According to the capsule type medical device of the present
invention, by changing the size of each electrode to secure optimum
electrode size for each electrode, sending of a desired amount of
currency to the body tissue becomes simple.
It is preferable that the capsule type medical device of the
present invention further include a wire storage unit for storing
the flexible wires inside the casing.
According to the capsule type medical device of the present
invention, the flexible wires are stored inside the casing when the
electrodes are not in use so that the flexible wires do not stick
out from the casing.
It is preferable that the capsule type medical device of the
present invention further include a rotation shaft which is
connected to the base ends of the flexible wires and is rotatably
supported inside the wire storage unit; and an actuator for driving
the rotation shaft.
According to the capsule type medical device of the present
invention, releasing or winding of the flexible wires is
accomplished through rotation of the rotation shaft by driving the
actuator, hence, interelectrode distance may be changed
arbitrarily.
In the capsule type medical device of the present invention, it is
preferable that the flexible wires possess a shape memory property,
and the flexible wires enter a coil-like wound state at 30.degree.
C. or a lower temperature, but returns to substantially straight
line at 35.degree. C. or a higher temperature.
According to the capsule type medical device of the present
invention, the flexible wires are under a near room temperature
condition (around 25.degree. C.) prior to introduction into the
living body, hence the flexible wires are stored in a coil-like
wound state in the wire storage unit. Moreover, after deployment
inside the living body, the flexible wires are under a near body
temperature condition (around 35.degree. C.), and the flexible
wires return to a near straight line state. Hence, once the capsule
type medical device is swallowed, the flexible wire may be
automatically unwound from the wire storage unit.
It is preferable that the capsule type medical device of the
present invention further include a heating device for heating
inside of the wire storage unit, and the flexible wires possess a
shape memory property by which they are restored to linear shape at
a temperature of 40.degree. or higher from a substantially
coil-like wound state.
According to the capsule type medical device of the present
invention, the flexible wires, prior to entering the living body,
are under a normal room temperature state (around 25.degree. C.),
hence, the flexible wires are stored in the wire storage unit in
nearly coil-like wound state around the rotation shaft. Even after
entering the living body, the flexible wires remain under body
temperature (around 35.degree. C.), which is lower than 40.degree.
C., hence, the flexible wires remain inside the wire storage unit
maintaining the original shape. Moreover, when the temperature
inside the wire storage unit is raised higher than 40.degree. C. by
the operation of heating device, the flexible wires are restored to
virtually linear shape. Hence, by driving the heating device to
operate after swallowing the capsule type medical device, it
becomes possible to unwind the flexible wires from the wire storage
unit at a desired location inside the living body.
It is preferable that the capsule type medical device of the
present invention further include a power source for supplying
electric power to the first electrodes, and wires, at least part of
which possess flexibility, for electrically and mechanically
connecting the power source and the electrodes, wherein the first
interelectrode distance variation device comprises an elastic
expansion unit which is expandable elastically and is mounted at
least partially on the casing, and the first electrodes are
provided on the elastic expansion unit.
According to the capsule type medical device of the present
invention, the electrodes are accurately made to contact, through
expansion of the elastic expansion unit at desired locations inside
the living body, the internal wall of lumenal organ such as
digestive tubes with non-uniform outer diameter Moreover, due to
bendability of the wire connecting the electrodes and the power
source, both expansion and contraction of the elastic expansion
unit may be dealt with. Furthermore, stable electric stimulation
may be provided with little interruption such as by wire
breaks.
It is preferable that the capsule type medical device of the
present invention further include an expansion device for expanding
the elastic expansion unit, wherein the expansion device is
provided separate from the casing, and is detachably mounted on the
casing.
According to the capsule type medical device of the present
invention, the structure of the casing may be simplified
substantially because the expansion device is provided separately
from the casing body.
In the capsule type medical device of the present invention, it is
preferable that the elastic expansion unit be detachably mounted on
the casing.
According to the capsule type medical device of the present
invention, the elastic expansion unit with optimum usage may be
mounted on the casing depending on usage of the capsule type
medical device. Moreover, it is easy, for example, to repeat use of
the relatively expensive main device and to dispose of the
relatively economical elastic expansion unit after each use.
In the capsule type medical device of the present invention, it is
preferable that a hard member which is harder than other parts of
the elastic expansion unit be provided on the elastic expansion
unit, and the first electrodes are provide on the hard member.
According to the capsule type medical device of the present
invention, if the electrodes are made of a material that does not
substantially expand or contract like metals and the like, mutual
difference in contraction and expansion rate between the electrodes
and the elastic expansion unit may be made small by mounting the
electrode in the hard unit. Hence, the electrode may be mounted and
maintained in the elastic expansion unit under better
conditions.
In the capsule type medical device of the present invention, it is
preferable that electric stimulation signals to be sent to the
electrodes be generated by the modulation of pulse signals of 100
Hz or less with pulse signals of 1000 Hz or more.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a drawing illustrating a basic configuration of a
capsule type medical device in the first embodiment of the present
invention, and is a side view of a capsule type medical device.
FIG. 1B is a drawing illustrating a basic configuration of the
capsule type medical device in the first embodiment of the present
invention, and is a back view of the capsule type medical
device.
FIG. 1C is a drawing illustrating a basic configuration of the
capsule type medical device in the first embodiment of the present
invention, and is a back view of a deformed example of the
electrodes and the flexible wires to be provided in the capsule
type medical device of FIG. 1A and FIG. 1B.
FIG. 2 is a block diagram showing the capsule type medical device
and an external device in the first embodiment of the present
invention.
FIG. 3 is a side view showing conditions of the capsule medical
device in the first embodiment of the present invention prior to
introduction into the living body.
FIG. 4A and FIG. 4B are schematic diagrams showing the manner in
which the capsule type medical device in the first embodiment of
the present invention is propelled inside the intestine.
FIG. 5 is a side view showing a first deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 6A is a side view showing a second deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 6B is a back view showing a second deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 7A is a side view showing a second deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 7B is a back view showing a second deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 8 is a side view showing a third deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 9 is an enlargement of major parts of the capsule type medical
device indicated by broken lines in FIG. 8.
FIG. 10A is a side view showing a fourth deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 10B is a back view showing a fourth deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 11A is a side view showing a fourth deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 11B is a back view showing a fourth deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 12A through FIG. 12C are drawings showing deformed examples of
the electrodes in the capsule type medical device of FIG. 10A and
FIG. 10B, and are cross-section near electrodes.
FIG. 13A is a side view showing a fifth deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 13B is a back view showing a fifth deformed example of the
capsule type medical device in the first embodiment of the present
invention.
FIG. 14A through FIG. 14E are schematic drawings showing deformed
examples of the electrodes in the capsule type medical device of
FIG. 13A and FIG. 13B.
FIG. 15A through FIG. 15C are schematic drawings showing the manner
in which the fifth deformed example of the capsule type medical
device is propelled inside the large intestine.
FIG. 16 is a side view showing a sixth deformed example of the same
capsule type medical device.
FIG. 17A is a drawing illustrating a basic configuration of capsule
type medical device in the second embodiment of the present
invention, and is a side view of the capsule type medical
device.
FIG. 17B is a drawing illustrating a basic configuration of capsule
type medical device in the second embodiment of the present
invention, and is a back view of capsule type medical device.
FIG. 18 is a block diagram illustrating capsule type medical device
in the second embodiment of the present invention.
FIG. 19 is an enlargement near the electrodes of the capsule type
medical device shown in FIG. 18.
FIG. 20A is a drawing illustrating a basic configuration of the
capsule type medical device in the second embodiment of the present
invention, and is a side view of the capsule type medical
device.
FIG. 20B is a drawing illustrating a basic configuration of the
capsule type medical device in the second embodiment of the present
invention, and is a back view of the capsule type medical
device.
FIG. 21 is a drawing showing introduction of the same capsule type
medical device inside the living body and conditions for giving
electric stimulation depending on location.
FIG. 22 is a drawing showing a position example of a photo screen
of stomach, small intestine, large intestine and anus photographed
by the capsule type medical device.
FIG. 23A is a side view showing a first deformed example of the
capsule type medical device in the second embodiment of the present
invention.
FIG. 23B is a back view showing a first deformed example of the
capsule type medical device in the second embodiment of the present
invention.
FIG. 24 is a partial cross-section showing a second deformed
example of the same capsule type medical device FIG. 25A is a side
view showing a third deformed example of the same capsule type
medical.
FIG. 25B is a back view showing a third deformed example of the
same capsule type medical device.
FIG. 26 is a drawing showing the structure of the capsule type
medical device in the third embodiment of the present
invention.
FIG. 27A and FIG. 27B are schematic diagrams showing a wave pattern
of the pulse signal to be sent to the electrodes when electric
stimulation is given to the body tissue.
FIG. 28A is a cross-section showing a first deformed example of the
capsule type medical device in the third embodiment of the present
invention.
FIG. 28B is a partial enlargement of the first deformation model of
the capsule type medical device shown in FIG. 28B.
FIG. 29A is a side view showing a second deformed example of the
capsule type medical device in the third embodiment of the present
invention.
FIG. 29B is a cross-section showing a second deformed example of
the capsule type medical device in the third embodiment of the
present invention.
FIG. 30 through FIG. 32 are side views showing a third deformed
example of the capsule type medical device in the third embodiment
of the present invention.
FIG. 33 through FIG. 34B are side views showing a fourth deformed
example of the capsule type medical device in the third embodiment
of the present invention.
FIG. 35 is a side view showing a fifth deformed example of the
capsule type medical device in the third embodiment of the present
invention.
FIG. 36 is a cross-section showing a sixth deformed example of the
capsule type medical device in the third embodiment of the present
invention.
FIG. 37 is a cross-section showing a seventh deformed example of
the capsule type medical device in the third embodiment of the
present invention.
FIG. 38 is a cross-section showing an eighth deformed example of
the capsule type medical device in the third embodiment of the
present invention.
FIG. 39 A through FIG. 39C are cross-section showing a ninth
deformed example of the capsule type medical device in the third
embodiment of the present invention.
FIG. 39D is a cross-section showing a movement member provided in
capsule type medical device shown in FIG. 39A through FIG. 39C.
FIG. 40A and FIG. 40B are side views showing a 10th deformed
example of the capsule type medical device in the third embodiment
of the present invention.
FIG. 40C is a cross-section showing a 10th deformed example of the
capsule type medical device in the third embodiment of the present
invention.
FIG. 41A and FIG. 41B are side views showing an 11th deformed
example of the capsule type medical device in the third embodiment
of the present invention.
FIG. 42A is a cross-section showing a 12th deformed example of the
capsule type medical device in the third embodiment of the present
invention.
FIG. 42B is an oblique view showing a 12th deformed example of the
capsule type medical device in the third embodiment of the present
invention.
FIG. 43A is a side view showing capsule type medical device in the
fourth embodiment of the present invention.
FIG. 43B and FIG. 43C are cross-sections showing partial
enlargement of the capsule type medical device shown in FIG.
43A.
FIG. 44A and FIG. 44B are side view showing conditions of the
capsule type medical device in the fourth embodiment being
introduced inside a body cavity.
FIG. 45A is a cross-section showing the capsule type medical device
in the fifth embodiment of the present invention.
FIG. 45B is a front view showing the capsule type medical device in
the fifth embodiment of the present invention.
FIG. 46A and FIG. 46B are side view showing partial cross-sectional
views of the endoscope in the sixth embodiment of the present
invention.
FIG. 47A through FIG. 47C are side views showing conditions of the
endoscope of the sixth embodiment of the present invention being
introduced in the living body cavity.
FIG. 48 is a side view showing the endoscope in the sixth
embodiment of the present invention.
FIG. 49A is a side view showing a deformed example of the endoscope
in the sixth embodiment of the present invention.
FIG. 49B is a cross-section showing a deformed example of the
endoscope in the sixth embodiment of the present invention.
FIG. 50A is a cross-section showing a deformed example of the
endoscope in the sixth embodiment of the present invention.
FIG. 50B and FIG. 50C are side views showing conditions of the
endoscope of the sixth embodiment of the present invention being
introduced in the living body cavity.
BEST MODES FOR CARRYING OUT THE INVENTION
Hereafter, embodiments of the capsule type medical device of the
present invention are shown with reference to the drawings.
The first embodiment of the present invention is shown with
reference to FIG. 1A through FIG. 15. The capsule type medical
device C1 shown in FIG. 1A through FIG. 2 is a basic configuration
of a capsule type medical device in the present embodiment. This
capsule type medical device C1 comprises a photography unit
(in-vivo information acquisition device) 2, control unit (current
control device) 3, radio transceiver unit (communication device) 4,
and battery 5 for supplying power to each structural unit as one
body inside a casing 1. Moreover, the capsule type medical device
C1 comprises a pair of electrodes 6 and flexible wires 7. Flexible
wires 7 play a role of interelectrode distance variation device
that changes a distance between the pair of electrodes 6.
The casing 1 has a capsule shape extending along axis L, and is
formed to seal the inside using plastic and the like. A semi-sphere
shaped transparent dome 1d is provided in the front section of the
casing 1. A photographing element 2a and light emitting element 2b
are arranged inside the transparent dome 1d, namely in the front
section (front side along axis line L). The photographing element
2a comprises a lens, a CCD (charge coupled device) and others for
acquiring a photo screen by photographing parts in the living body.
The light emitting device 2b comprises an EL (electroluminescence
element), LED (light emitting diode) and others for illuminating a
scope of vision of the photographing element 2a by radiating light.
The photography unit 2 that acquires in-vivo information by
photographing inside the living body comprises a photographing
element 2a and the light emitting element 2b.
The radio transceiver unit 4 comprises a transmission/reception
main body, which is unrepresented, and a transmission/reception
antenna (a transmission antenna and a reception antenna) that
transmit and receive radio wave. The radio transceiver unit 4 radio
transmits in-vivo information, namely the photo screen photographed
by the photographing element 2a to an external device 100, to be
explained later. Moreover, the radio transceiver unit 4 receives
control signals (commands), to be explained later, radio
transmitted from the external device 100 and transmits them to the
control unit 3.
The control unit 3 possesses a function for comprehensively
controlling operations of each part within the capsule type medical
device C1 based on the control signals (commands) from the radio
transceiver unit 4. Moreover, in the control unit 3, a current
generation circuit 3a is provided for sending current to the
electrodes 6 through flexible wires 7. In other words, the control
unit 3 possesses a function as current control device for
controlling current to be sent to the electrodes 6.
The flexible wires 7 are made of flexible conductive member, and
its base end is supported respectively at the rear side (the other
end along axis L) of the casing 1. The flexible wires 7 protrude
from the casing 1 in a manner such that each wire is separate from
the other wire with the tip of each wire supporting an electrode 6.
In other words, the electrodes 6 are arranged in the rear side of
the casing through the flexible wires 7. The flexible wires 7 are
connected to the control unit 3 in the casing 1 and send current
from the current generation circuit 3a to the respective electrodes
6. Moreover, the flexible wires 7 possess function for changing the
distance between the electrodes through elastic deformation. This
function enables accurate compensation for lumenal organ diameter
in the living body. The flexible wires are preferably made of super
elastic alloy. Use of super elastic alloy for the flexible wires
makes flexible wires 7 more flexible than normal metal, hence,
change of the lumenal organ diameter in the living body is more
infallibly absorbed.
The electrodes 6 make contact with body tissue and give electric
stimulation to the body tissue. They have a virtually spherical
shape in order not to block propelling of the capsule type medical
device C1. The electrodes 6 are made of at least one material out
of stainless steel, platinum, and titanium, all of which have high
electric conductivity and enable effective current flow. Moreover,
it makes the electrodes highly compatible with the living body.
The maximum distance of separation between the electrodes 6, namely
the maximum value (X) of the distance between the electrodes that
changes because of the flexible wires 7 are preferably more than
double (X.gtoreq.2D) the outer diameter (D) of the capsule type
medical device C1, as shown in FIG. 1A and FIG. 1B. Making the
outer diameter of the capsule type medical device C1 needlessly
large is not preferable, considering ease of introducing it inside
of the living body. For example, around 10 mm (preferably around 11
mm) is proper. However, even the small intestine, which is
considered to have one of the smallest inner diameters among the
lumenal organ organs, has an inner diameter of around 20.about.30
mm. For this reason, the maximum separation distance between the
electrodes 6 should be more than double (preferably more than 3
times) the outer diameter of capsule type medical device, in order
for the electrodes 6 to accurately give electric stimulation to the
body tissue inside the lumen.
Moreover, the flexible wires 7 may comprise conductive wire member
that sends current from the base end to the tip side, and an
insulation member such as resin to insulate and cover the
conductive wire member. Or, bare conductive wire member may be
integrated with the electrodes 6 to give electric stimulation to
the body tissue. If the conductive wire member is bare, greater
electric contact area is secured for sending current, and a
constant amount of current needed for electric stimulation may be
supplied in giving electric stimulation to the body tissue. Here,
the flexible wire may be made to have a belt shape such as the wire
denoted 7w and the electrodes may be made to be wider electrodes 6w
with virtually the same width as the flexible wires as shown in
FIG. 1C. By doing this, an even greater electric contact area is
obtained and more stable supply of current to the body tissue
needed for contraction may be obtained.
Moreover, the conductive wires themselves are not highly elastic
like a super elastic alloy, and the insulation member that covers
and insulates the conductive wire member is made of resin (super
elastic polymer material) and the like with super elasticity. As a
result super elasticity may be provided to the flexible wires 7.
Furthermore, one pair of electrode 6 and flexible wire 7
combinations is arranged around the capsule type medical device at
a 180.degree. interval, but two pairs of electrodes (total of 4)
may be arranged at 90.degree. intervals. This enables more accurate
contact of electrodes 6 with the body tissue.
The external device 100 controls the capsule type medical device
from outside of the living body. The external device 100, as shown
in FIG. 2, comprises, within the main body of the device (101), a
radio transceiver unit (a transmission unit and a detection unit)
102 for transmitting and receiving information to and from the
capsule type medical device C1, a recording unit 103 such as memory
for storing the aforementioned in-vivo information, namely photo
images, a control unit 104 for controlling each unit, and a battery
105 for supplying power to each unit.
The main body of the device 101 is formed in a box shape with metal
such as aluminum, and plastics, and is mountable on the person
being examined using a belt and others. With this, the person being
examined may always wear the external device 100 on the living
body. The radio transceiver unit 102, like the radio transceiver
unit 4 of the capsule type medical device C1, comprises an
unrepresented main body of a transmission/reception unit and
transmission/reception antenna (a transmission antenna and a
reception antenna) for transmitting and receiving radio waves. The
radio transceiver unit 102 receives in-vivo information, namely
photo images, radio transmitted from the capsule type medical
device C1 and transmits the images to the control unit 104.
The control unit 104 executes a predetermined process such as image
processing on the photo images received, after which it records the
images in recording unit 103 at all time. Moreover, a position
detection circuit 104a for detecting the location of the capsule
type medical device C1 inside the living body is embedded in the
control unit 104. In the position detection circuit 104a, a setting
image (reference image) is preset, and by comparing received photo
images with the setting image, the circuit detects the position of
the capsule type medical device C1 within the living body. Here,
the position detection circuit 104a detects the position of the
capsule type medical device C1 by comparing the photo images with
the setting image, and the position of the capsule type medical
device C1 may be detected based on predetermined colors, shapes and
other features within photo images.
Moreover, the position detection circuit 104a may detect the
position based on, rather than photo images, intensity of radio
waves being transmitted from the radio transceiver unit 4 to
outside of the living body, or received from outside of the living
body. In this case, a plurality of antenna is provided on the radio
transmission/reception at external device 100 side, and the
position is computed through triangulation or the like based on
positions of the plural antennas and the intensity of radio waves.
Furthermore, the position may be computed by mounting a magnetic
field generation coil or magnetic sensor on the capsule type
medical device C1 or external device 100 and detecting an
externally magnetic field generated in the living body or detecting
internally a magnetic field generated outside the living body.
Moreover, the control unit 104 transmits control signals
corresponding to the body tissue (for example, stomach, small
intestine or large intestine) surrounding the capsule type medical
device, whose position is detected by the position detection
circuit 104a, through the radio transceiver unit 102.
Next, a case in which the inside of the living body of the person
being examined using the capsule type medical device C1 with the
aforementioned structure is shown.
First the person being examined wears the external device 100 using
a belt and the like. Then the person orally takes (swallows) the
capsule type medical device C1 to deploy capsule type medical
device C1 inside the living body. Prior to swallowing the capsule
type medical device C1, the flexible wires 7 are mutually
pre-bundled using wire bundling bands (wire bundling device) made
of body absorbable material such as starch, as shown in FIG. 3.
This minimizes obstruction that may be caused by the flexible wires
7 and electrodes 6 during swallowing of the capsule type medical
device C1. A unrepresented switch is provided in the capsule type
medical device C1. The switch is turned on when swallowing the
capsule type medical device C1, enabling power supply from the
battery 5 to each component. With this, the control unit 3 drives
the photography unit 2, namely the photographing element 2a and
light emitting element 2b.
The capsule type medical device C1 introduced inside the living
body photographs parts inside the living body using the
photographing element 2a as the device moves inside the digestive
tubes. At the same time, it transmits photo images from the radio
transceiver unit 4 towards the external device 100. Meanwhile, the
external device 100 receives the photo images through the radio
transceiver unit 102, and executes image processing of the photo
images using the control unit 104 and the images are continually
recorded in recording unit 103. The control unit 104 continually
transmits control signals corresponding to the body tissue (for
example, stomach, small intestine or large intestine) surrounding
the capsule type medical device, whose position is detected by the
position detection circuit 104a, through the radio transceiver unit
102
Upon arrival at the stomach, the wire bundling band 7B of the
capsule type medical device C1 is dissolved by stomach acid and is
absorbed inside the living body. This frees the electrodes 6 and
flexible wires 7 from their bundled condition, causing changes in
the distances between the electrodes. From here, the operator,
while watching the photo images, propels the capsule type medical
device C1 by giving electric stimulation as needed to body tissue
such as the stomach, small intestine, large intestine and others.
In fact, rapid changes of the photo images indicate that the
capsule type medical device C1 is moving too fast. Hence, the
operator reduces the number of times the current is sent to the
electrodes 6 to reduce the speed of the capsule type medical device
C1. On the other hand, little change in the photo images indicates
that the capsule type medical device C1 is hardly moving. Hence,
the operator raises the frequency of sending current to the
electrodes 6, which increases the moving speed of the capsule type
medical device C1.
Next, conditions of the capsule type medical device C1 reaching the
small intestine I after passing through the stomach and the
duodenum are shown in FIG. 4A and FIG. 4B. In this case, with
reception of control signals from the external device 100
commanding to give electric stimulation, the control unit 3 sends
current to the electrodes 6 and gives electric stimulation to the
wall Iw of the small intestine I, as shown in FIG. 4B. The small
intestine I near the location of the electric stimulation
contracts, which causes forward propelling of the capsule type
medical device being pushed by the contraction of the small
intestine I, as shown in FIG. 4B. At this time, the flexible wires
elastically deform with the contraction of the small intestine I,
and change in the diameter of the small intestine I is accurately
compensated. With this, the capsule type medical device moves
inside the small intestine I more accurately than with autonomic
peristaltic movement of the small intestine I. Hence, time required
for observation is shortened, enabling efficient observation of the
inside of the intestine.
The capsule type medical device C1 next passes through the large
intestine in a manner similar to the above, and is discharged from
the anus to outside the living body. Doctors and others examine the
health condition of the person based on the in-vivo information,
namely the photo images, recorded in the recording unit 103 of the
external device 100.
Unlike estimating the moving speed of the capsule type medical
device C1 from changes in photo images as shown above, a moving
speed detection device such as a velocity sensor or an acceleration
sensor for detecting a moving speed of the capsule type medical
device may be provided to adjust amount and timing of current for
electric stimulation only inside the capsule type medical device C1
based on the detection results of the sensor. With this, the
capsule type medical device C1 may be automatically moved at a
constant speed and acquire in-vivo information independent of the
external device 100. The external device 100 is required only to
receive and record in-vivo information acquired by the capsule type
medical device C1, and hence processing becomes simple.
Moreover, because processing of the photo images is not executed,
mounting of the photo sensor onto the capsule type medical device
C1 becomes unnecessary. Hence, a in-vivo information acquisition
sensor possessing functions other than photo functions may be
installed without problems on the capsule type medical device.
Incidentally, the in-vivo information acquisition sensor may
include a pH sensor for acquiring pH in the living body, a super
sound wave sensor, alight shielding layer sensor for acquiring a
cross-section image inside the walls of lumenal organs, a microwave
image sensor for making specific body tissue like cancer into an
image, temperature sensor for detecting temperature, a bleeding
sensor for detecting bleeding inside the living body, a chemical
sensor for detecting chemical substance such as enzyme produced by
specific disease areas, and a chemical sensor for detecting the
presence and amount of bacteria inside the intestine.
Because this capsule type medical device C1 comprises flexible
wires 7 as interelectrode distance variation device for changing
the distance between the electrodes, the electrodes 6 are
accurately made to contact the body tissue, giving electric
stimulation. This enables the body tissue to accurately execute
contraction action. Hence, stable propelling of the capsule type
medical device C1 may be achieved.
Moreover, because the electrodes 6 are made of stainless steel,
platinum, titanium or other material, high electric conductivity
and efficient current flow are achieved. Furthermore, high body
compatibility is given to electrodes 6.
Moreover, because the interelectrode distance variation device
comprises flexible wires that protrude outward with base ends being
supported by the casing 1, and tip ends supporting electrodes 6,
the structure of the interelectrode distance variation device is
simple. Besides, the flexible wires 7 easily deform elastically.
Hence, with deployment of the capsule type medical device C1 inside
the lumenal organ, changes in the lumenal organ diameter are
accurately compensated, and the electrodes 6 are accurately made to
contact the body tissue.
Moreover, when the flexible wires 7 are made of super elastic
alloy, great deformation of the flexible wires becomes possible,
which enables more accurate compensation of changes in lumenal
organ diameter inside the living body.
Moreover, because the tip ends of the flexible wires 7 are mutually
bundled with the wire bundling band 7B made of living body
absorbing material, the electrodes 6 and the flexible wires 7 do
not cause problems when the capsule type medical device C1 is
swallowed, enabling easy deployment of the capsule type medical
device inside the living body. After the capsule type medical
device is swallowed, the wire bundling band 7B is dissolved by
stomach acid and is absorbed in the living body. Thus the bundle
between the flexible wires 7 is loosed, enabling changes in the
distance between the electrodes 6.
Next, deformed examples of the capsule type medical device C1 in
the aforementioned first embodiment are shown.
Here, each structural element such as the photography unit 2 (photo
element 2a and light emitting element 2b), control unit 3, radio
transceiver unit 4 and battery 5 of the capsule type medical device
C1 is a common structural element provided in a similar manner in
each of the deformed examples of the capsule type medical device
below. Hence, in the following example, presentations and detailed
descriptions of these structural elements are omitted. Moreover,
other structural elements similar to those in the capsule type
medical device C1 are denoted with the same symbols and detailed
descriptions of those are omitted.
FIG. 5 illustrates the first deformed example.
In the capsule type medical device C2, a pair of front side
electrodes (second electrodes) 8 are provided on the front side
(the other edge side along the xis) of the casing 1 of the
aforementioned capsule type medical device C1. Moreover, flexible
front side wires 9 are provided as second interelectrode distance
variation device that change the distance between the pair of front
side electrodes 8. These front side electrodes 8 and front side
flexible wires 9 possess virtually the same structure as the
electrodes 6 and the flexible wires 7.
The base ends of the front side flexible wires 9 are supported at
the front side (the other end along axis L) of the casing 1 but at
the rear side of the transparent dome 1d. The front side flexible
wires 9 protrude externally from the casing 1 in a manner such that
each wire may move away from the other and supports a front side
electrode 8. In other words, the electrodes 8 are provided through
flexible wires 7 at the front side of the casing 1, separate from
the photography unit 2. Hence, the electrodes 8 do not block
photographing by the photography unit 2.
Moreover, the front side flexible wires 9 are connected to the
control unit 3 (shown in FIG. 2) inside the casing 1 and send
current from the current generation circuit 3a to each of the front
side electrodes 8, and change the distance between the front
electrodes 8 by way of elastic deformation. The control unit
possesses a function as second current control device that controls
current to be sent to the front side electrodes 8 based on control
signals (commands) from the radio transceiver unit 4, independent
of control of the current to be sent to the electrodes 6.
In the capsule type medical device C2, the front side electrodes 8
and front side flexible wires 9 are provided in the front separate
from the electrodes 6 and flexible wires 7 that are provided in the
rear of the casing 10 with current to be sent being controlled
independently, enabling free forward and backward movement of the
capsule type medical device C2 inside the living body. In other
words, the capsule type medical device C2 moves forward by way of
electric stimulation of the body tissue through the electrodes 6
provided at the rear side of the casing 1, and moves backward by
way of electric stimulation of the body tissue through the front
side electrodes 8 provided at the front side of the casing 1. With
this, the operator can move the capsule type medical device C2 in
lumenal organ such as the small intestine and large intestine, for
example, forward or backward as needed while watching the photo
images, which improves operation capability. Moreover, the operator
can easily handle the device without regard to which direction,
front side or rear side, of a narrow lumenal organ, the capsule
type medical device C2 enters from. Furthermore, because forward
and backward movement are both available, any possible location in
the lumenal organ may be observed.
Here, the control unit 3 possesses functions as both first current
control device and as second current control device, but two
control units 3 may be provided with one functioning as first
current control device and the other as second current control
device. Moreover, the photographing unit may be provided at the
rear part of the casing 1. With this, any possible location in the
lumenal organ can be observed.
FIG. 6A through FIG. 7B shows the second deformed example.
The structure of the casing 11 of the capsule type medical device
C3 is different from that of the casing of the aforementioned
capsule type medical device C1. In the casing 11 of the capsule
type medical device C3, a groove 11a is formed along the outer
circumference for storing the electrodes 6 and the flexible wires
7. Prior to deployment of the capsule type medical device C3 inside
the living body, the electrodes 6 and flexible wires 7 are anchored
beforehand inside the groove 11a with wire binder (wire anchoring
device) made of living body absorbing material such as starch, as
shown in FIG. 6A and FIG. 6B. With this, the flexible wires 7 and
electrodes 6.6 do not become obstacles when the capsule type
medical device C3 is swallowed.
Upon arrival in the stomach, the wire binder of the capsule type
medical device C1 is dissolved by stomach acid and is absorbed
inside the living body. This frees the electrodes 6 and flexible
wires 7 from their bundled condition, causing change in the
distance between the electrodes 6, as shown in FIG. 7A and FIG.
7B.
In the capsule type medical device C3, the groove 11g is formed
along the outer circumference of the casing 11 for storing the
electrodes 6 and the flexible wires 7. Hence, the flexible wires 7
are stored in such a manner that the space of storage is minimized
and the flexible wires 7 do not stick out from the outer surface of
the casing 11 when the electrodes 6 are not in use.
Moreover, because a wire binder 11B made of living body absorbing
material is used to anchor the electrodes 6 and flexible wires 7
inside the groove 11g, the electrodes 6 and the flexible wires 7 do
not become obstacles when the capsule type medical device C3 is
swallowed, enabling easy deployment inside the living body. After
deployment, the wire binder 11B is dissolved by stomach acid and is
absorbed in the living body, the electrodes 6 and the flexible
wires 7 are loosed, and the distance between the electrodes 6
changes freely. Hence, precise operation of the electrodes 6 and
the flexible wires inside the living body is achieved.
FIG. 8 and FIG. 9 describe the third deformed example.
The structure of the casing 12 of the capsule type medical device
C4 is different from that of the casing of the aforementioned
capsule type medical device C1. In addition, the structure of the
flexible wires 71 is different from that of the flexible wires of
the aforementioned capsule type medical device C1. In the casing 12
of the capsule type medical device C4, a wire storage units 21 are
provided for storing the flexible wires 71 and the electrodes 6
separately inside the casing 12.
The wire storage units 21 have openings 21h formed in a cave shapes
in the rear section of the casing 12. The electrodes 6 and the
flexible wires 71 can appear in or disappear from the outside
through the opening 21h. Rotation shafts 21r, free to rotate, are
supported inside the wire storage units 21. Each of the base ends
of the flexible wires 71 are connected to rotation shaft 21r.
Current flows from the control unit 3 to the electrodes 6 through
the rotation shaft 31r and flexible wires 71.
The flexible wires 71 are made of shape memory alloy and are given
shape memory characteristics wherein they are in a coil-like wound
state under a temperature of 30.degree. C. or less, but return to
nearly linear shape under a temperature of 35.degree. C. or above.
Prior to deployment of the capsule type medical device C4 into the
living body, the flexible wires 71 are under room temperature
(around 25.degree. C.), and the flexible wires 71 are stored in the
wire storage units 21 under their substantially coil-like wound
state. Moreover, after deployment of the capsule type medical
device C4 inside the living body, the flexible wires 71 are under a
near body temperature condition (around 36.degree. C.), and the
flexible wires return to a near straight line state. Hence, once
the capsule type medical device C4 is swallowed, the flexible wires
71 may be automatically unwound from the wire storage units 21.
In the capsule type medical device C4, the electrodes 6 and
flexible wires 71 are stored inside the electrode storage units 21
in a manner such that no objects protrude from the casing 12 when
the capsule type medical device C4 is swallowed, enabling easy
swallowing of the capsule type medical device C4. After the capsule
type medical device is introduced into the living body and the
temperature rises to near body temperature, the electrodes 6 and
the flexible wires 71 are unwound and operate, and electric
stimulation is accurately given to body tissue.
The capsule type medical device of the present invention preferably
further comprises heating device for heating the inside of the wire
storage units, and the flexible wires preferably possess a shape
memory property that restores linear shape under a temperature of
40.degree. or higher from the substantially coil-like wound
state.
Here, shape memory characteristics for restoring the flexible wires
71 to nearly linear shape at a temperature of more than 40.degree.
C. from their coil-like wound state, may be given to the flexible
wires 71. In addition, a heating device that is controlled by the
control unit 3 and heats the inside of the wire storage units 21
may be provided (unrepresented). If the flexible wires 71 are made
to memorize such shape before the capsule type medical device 4 is
introduced into the living body, because the flexible wires 71 are
under room temperature (around 25.degree. C.) before deployment
into the living body, the flexible wires 71 may be stored in a
substantially coil-like wound state around the rotation shaft 21r.
Even after entering the living body, the flexible wires 71 remain
under body temperature (around 35.degree. C.), which is lower than
40.degree. C., hence, the flexible wires 71 remain inside the wire
storage units 21 maintaining the original shape. Moreover, when the
temperature inside the wire storage unit s21 is raised higher than
40.degree. C. by the operation of heating device, the flexible
wires are restored to linear shape. Hence, by driving the heating
device to operate after swallowing the capsule type medical device
C4, it becomes possible to unwind the flexible wires from the wire
storage units 21 at desired location inside the living body.
In the capsule type medical device C4, the electrodes 6 and the
flexible wires 71 are stored inside the electrode storage units 21
in a manner such that no objects protrude from the casing 12 when
the capsule type medical device C4 is swallowed, enabling easy
swallowing of the capsule type medical device C4. By making the
heating device operate after the capsule type medical device C4 is
introduced into the living body, the electrodes 6 and flexible
wires 71 are unwound and operate, and electric stimulation is
accurately given to the body tissue.
FIG. 10A through FIG. 12C describe the fourth deformed example.
The structure of the interelectrode distance variation device of
this capsule type medical device C5 is different from the
interelectrode distance variation device of the aforementioned
capsule type medical device C1. This capsule type medical device C5
comprises a pair of outer shell units 72a, 72b. On this pair of
outer shell units 72a, 72b, a plurality of electrodes are anchored,
and the pair of outer shell units 72a, 72b are installed outside of
the casing 13 in such a manner that the outer shell units move away
from each other outwardly relative to the casing 13.
Each of the outer shell units 72a, 72b has a hemisphere shape and
is installed on the casing 13 in such a manner that the hemisphere
covers from near the center along the length through the rear edge
section of the casing 13. In the state where the outer shell units
72a, 72b are closed, the near center through the rear edge section
along the length of the casing 13 is covered by the outer shell
units 72a, 72b, as shown in FIG. 10A and FIG. 10B. Between the
outer shell units 72a, 72b and the casing 13, springs 72s that push
each of the outer shell units 72a, 72b externally in radial
direction are mounted. Moreover, a plurality of electrodes 61 is
anchored outside of the outer shell units 72a, 72b. Each electrode
61 is electrically connected to the control unit 3, from which
current flows.
Moreover, in the capsule type medical device C5, engaging device
(unrepresented), controlled by the control unit 3, for retaining
and releasing the outer shell units 72a, 72b are provided. Before
the capsule type medical device C4 is introduced to the living
body, the outer shell units 72a, 72b are stopped in the closed
state by the engaging device as shown in FIG. 10A and FIG. 10B.
After the capsule type medical device C4 is introduced into the
living body, the control unit 3 controls the engaging device, which
releases the engaged condition of the outer shell units 72a, 72b,
as shown in FIG. 11A and FIG. 11B. The outer shell units 72a, 72b
move outward and begin operation, being pushed by the springs 61s,
enabling free change in the distance between the electrodes 61.
In the capsule type medical device C5, a plurality of electrodes 61
is mounted on the outer shell units 72a, 72b, which are made to
move as one body outward and inward, and the electrodes 61 are
accurately made to contact the body tissue. Moreover, if, for
example, pressure from the lumenal organ is stronger than momentum
of the springs 72s, the outer shell units 72a, 72b move in such a
manner that the outer shell units close as needed, enabling stable
propelling of the capsule type medical device C5.
FIG. 12A through FIG. 12C shows deformed examples of the electrodes
61. The electrode 61a is a hemisphere shaped electrode protruding
from the outer surface of the outer shell units 72a, 72b, as shown
in FIG. 12A. With such an electrode, contact with the body tissue
becomes easy. Moreover, because there are no corners, smooth
propelling of the capsule type medical device C5 in the lumenal
organ is achieved.
The electrode 61b is a column-shaped electrode protruding from the
outer surface of the outer shell units 72a, 72b, as shown in FIG.
12B. With such an electrode, contact area with body tissue expands
and electric stimulation may be accurately given even to body
tissue such as a mucous membrane.
The electrode 61c is an electrode embedded in the outer shell units
72a, 72b in such a manner that the electrodes from smooth
continuation with the outer surface of the outer shell units 72a,
72b, as shown in FIG. 12C. With such an electrode, no part
protrudes from the outer surface of the outer shell units 72a, 72b,
and smooth propelling of the capsule type medical device C5 is
achieved.
Virtually the entire outer shell units 72a, 72b may be made into
electrodes, though this configuration is unrepresented. In such a
case, protrusion of electrodes is eliminated, hence, smoother
propelling of the capsule type medical device C5 in the lumenal
organ is achieved while maintaining stable electric contact
area.
Here, the outer shell units 72a, 72b may be engaged in the casing
13 after the outer shell units 72a, 72b begin operation.
In place of the springs 72s, water absorbing gel may be mounted
between the outer shall units 72a, 72b and the casing 13. When the
capsule type medical device C5 with water absorbing gel is
introduced into the living body, the water absorbing gel swells by
absorbing water in the living body, which causes movement of the
outer shell units 72a, 72b outward, enabling accurate alteration of
the distance between the electrodes 61 with a simple structure. As
another configuration, the springs 72s may be made of shape memory
alloy, and the springs 72s may expand with temperature inside the
living body to make the outer shell units 72a, 72b move.
FIG. 13A through FIG. 15 shows a fifth deformed example.
The capsule type medical device C6 comprises a large number of
electrodes and flexible wires, as well as a device for selecting
electrodes to which current is sent (an electrode selector).
As shown in FIG. 13A and FIG. 13B, a large number of electrodes 6
and flexible wires 7 are provided at the rear section of the casing
14 in capsule type medical device C6 at substantially the same
interval along the perimeter of the casing 14. The base ends of the
flexible wires 7 are connected to the electrode selector provided
in the casing 14. The electrode selector 6s is controlled by the
control unit 3, and selects a pair of electrodes out of the many
electrodes 6, to which current is sent. Current from the control
unit 3 is sent to a pair of electrodes 6 through the electrode
selector 6s and the flexible wires 7.
FIG. 14A through FIG. 14E shows a sixth deformed example of the
electrode 6.
The electrodes 6 shown in FIG. 14A are nearly spherical. The
electrodes 5a shown in FIG. 14B are a hook shape. The electrodes 6b
shown in FIG. 14B are a ring shape. The electrodes 6c shown in FIG.
14B are a rod shape. The electrodes 6d shown in FIG. 14E are made
wide to secure greater contact area. Different electrodes are
selected depending on the usage model of the capsule type medical
device C6.
FIG. 15A through FIG. 15C show conditions wherein the capsule type
medical device C6 with the above structure reaches the large
intestine R. In relatively large lumenal organ such as the large
intestine R, it often becomes necessary to move the capsule type
medical device C6 front and back as well as left and right, and to
change the field of vision. In moving the capsule type medical
device C6 left and right, by selection of electrodes 6 that are in
opposite direction from a desired propelling direction and making
contact with the lumenal wall (intestine wall Rw) of electrodes to
which current is sent, the capsule type medical device C6 is
propelled in combined directions of front and back as well as left
and right. Here, selection of electrodes 6 making contact with the
intestine wall Rw may be achieved by sending very weak trial
current to each electrode 6 and measuring the impedance each time
to find the electrode 6 that is making contact with the intestine
wall Rw.
In the capsule type medical device C6, many electrodes 6 and
flexible wires 7 are provided in the casing 14, and electrodes to
which current is sent are selected from the many electrodes 6.
Hence, left and right movement of the capsule type medical device
C6 is assured, enabling observation inside lumenal organ at every
possible location.
FIG. 16 shows a sixth deformed example.
The capsule type medical device C7 comprises electrodes arranged on
virtually the entire surface of the outer shell units 72a, 72b
wherein the electrodes are divided into groups of many electrodes
61a. Electrodes to which current is sent are selected arbitrarily
among the many electrodes 61a.
The many electrodes 61d are plane-shape electrodes which are
arranged densely on the outer surface of the outer shell units 72a,
72b. A group of positive and negative poles to be paired are
provided with positive poles and negative poles separated by pole.
The many electrodes 61d are connected to the electrode selector 6s2
provided inside the casing 13. The electrode selector 6s2, like the
aforementioned electrode selector 6s in the capsule type medical
device C6, is a device capable of arbitrarily selecting electrodes,
among the many electrodes 61d, to which current is sent. The
electrode selector 6s2 selects one or more groups of positive and
negative poles to be paired, and simultaneously sends current to
all the electrodes selected. If a fewer number of electrodes is
selected by the electrode selector 6s2, an area of electrodes to
give electric stimulation to the body tissue is small, and if a
larger number is selected, the electrode area is large.
In the capsule type medical device C7, an electrode area for giving
electric stimulation to the body tissue changes with pole, and the
optimum location of the electrodes may be selected and optimum
electrode area may be secured by pole. This enables easy supply of
a desired amount of current to the body tissue. Hence, the
electrode area for sending an amount of current needed for
effective contraction of the intestine, for example, is secured,
and at the same time, electrodes with favorable contact conditions
with the body tissue such as the inner intestine wall may be
selected.
The second embodiment of the present invention is shown with
reference to FIG. 17A through FIG. 25B. Here, structural elements
that are similar to those in the first embodiment are denoted with
the same symbols and the detailed descriptions thereof are
omitted.
As shown in FIG. 17A through FIG. 20B, the capsule type medical
device C10 is a basic configuration of the capsule type medical
device in the present embodiment. The capsule type medial device
C10 is capable of arbitrarily unwinding and winding the flexible
wires and electrodes in the medical device C4 as in aforementioned
first embodiment. In fact, motors (actuators) M as well as rotation
shafts 22r which are driven by motors M in place of the rotation
shafts 22r which rotate freely are provided in the capsule type
medical device C4.
Two motors M are arranged respectively near wire storage units 21
inside the casing 12 and are controlled by the control unit 3.
Rotation driving power of these motors M is transmitted to the
rotation shafts 22r through power transmission device such as
gears. In other words, the motors M and rotation shafts 22r
constitute unwinding/winding mechanisms for the flexible wires 7.
The motors M are controlled by external control signals and drive
the electrodes 6 by unwinding the flexible wire at arbitrary
locations. Or, the motors M completely store the flexible wires 7
and electrodes 6 inside the wire storage unit 21 by winding the
flexible wires 7. For the motors M, any motor/actuator such as an
electromagnetic motor, super sound wave motor, or static electric
motor may be used.
Here, the capsule type medical device C10, unlike the
aforementioned capsule type medical device C4, does not unwind/wind
the flexible wires utilizing automatic shape change of the flexible
wires. Hence, it uses flexible wires 7 made of super elastic alloy
and others, like the capsule type medical device C1, without using
shape memory alloy for the flexible wires.
FIG. 17A and FIG. 17B show a condition wherein nearly all the
flexible wires 7 are wound, and the electrodes 6 and the flexible
wires 7 are completely stored in the wire storage units 21. The
flexible wires 7 are kept in this condition when the capsule type
medical device C10 is swallowed or discharged from the anus, which
will be explained further later. Meanwhile, the condition in which
the flexible wires 7 are completely unwound, and the electrodes 6
and flexible wires 7 are in operation is shown in FIG. 20A and FIG.
20B. The flexible wires 7 are in this condition when the capsule
type medical device reaches the stomach and others, which will be
explained further later.
Here, the amount of unwinding and winding of the flexible wires 7
may be arbitrarily changed by control of the motor M, and it is
possible to create a condition wherein the flexible wires 7 are
unwound slightly from total storage and only the electrodes 6
protrude from the openings 21h, as shown in FIG. 19, for
example.
Next, observation inside the living body of a person using the
capsule type medical device C10 with the aforementioned structure
is shown.
First the person being examined wears the external device 100 using
a belt and the like. Then the person orally takes the capsule type
medical device C10 to deploy the capsule type medical device C1
inside the living body. Prior to swallowing the capsule type
medical device C10, the flexible wires 7 and the electrodes are
completely stored in the wire storage units 21, as shown in FIG.
17A and FIG. 17B. This minimizes obstruction that may be caused by
the flexible wires 7 and electrodes 6 during swallowing of the
capsule type medical device C1. An unrepresented switch is provided
in the capsule type medical device C1. The switch is turned on when
swallowing the capsule type medical device C1, enabling power
supply from the battery 5 to each component. With this, the control
unit 3 drives the photography unit 2, namely the photographing
element 2a and the light emitting element 2b.
The capsule type medical device C10 introduced inside the living
body photographs parts inside the living body using the
photographing element 2a as the device moves inside the digestive
tubes. At the same time, it transmits photo images from the radio
transceiver unit 4 towards the external device 100. Meanwhile, the
external device 100 receives the photo images through the radio
transceiver unit 102, and executes image processing of the photo
images using the control unit 104 which is recorded in recording
unit 103 at all time. The control unit 104 transmits control
signals corresponding to the body tissue (for example, stomach,
small intestine or large intestine) in which the capsule type
medical device C100 is present at all time, whose position is
detected by the position detection circuit 104a, through the radio
transceiver unit 102
When the capsule type medical device C10 reaches the stomach (see
FIG. 21(1)), the photographing element 2a takes pictures inside the
stomach and sends the photo images to the external device 100 (see
FIG. 22 (1)). The position detection circuit 104a confirms that the
capsule type medical device C10 is in the stomach by comparing the
photo images received and the setting image on brightness, color
frequency distribution, surface condition of the mucous membrane,
and the like. Because the stomach is an organ with a large lumen,
the control unit 104 drives the electrodes 6 and the flexible wires
7 to their utmost capacity, as shown in FIG. 21 and FIG. 22.
Moreover, the control unit 104 transmits control signals through
the radio transceiver unit 102 to give electric stimulation to the
body tissue through the electrodes 6. With such electric
stimulation, peristaltic motion of the stomach is induced and local
muscle contraction occurs. The capsule type medical device C10 is
propelled by the peristaltic motion of the stomach and local muscle
contraction, passes through the stomach, and reaches the
duodenum.
When the capsule type medical device C10 reaches the duodenum, the
photographing element 2a takes picture inside the duodenum and
sends the photo images to the external device 100. The position
detection circuit 104a confirms that the capsule type medical
device C10 is in the duodenum by comparing the photo images
received and the setting image. Responding to this, the control
unit 104 sends signals through the radio transceiver unit 102 to
wind the flexible wires 7. The capsule type medical device C10,
upon receiving the control signals, winds the flexible wires 7,
then unwinds the flexible wires 7 slightly from the wire storage
units 21, leaving only the electrodes 6 protruding from the
openings 21r.
When the capsule type medical device C10 passes through the
duodenum and reaches the small intestine (see FIG. 21(2)), the
photographing element 2a takes pictures inside the small intestine
and sends the photo images to the external device 100 (see FIG.
22(2)). The position detection circuit 104a confirms that the
capsule type medical device C10 is in the small intestine by
comparing the photo images received and the setting image, in a
manner similar to above. Responding to this, the control unit 104
sends signals through radio transceiver unit 102 to give electric
stimulation to the body tissue through the electrodes 6 or to wind
the flexible wires 7 as needed. The capsule type medical device
C10, upon receiving the control signals, gives electric stimulation
to the body tissue through the electrodes 6 or winds or unwinds the
flexible wires 7 as needed. From here, the operator, while watching
the photo images, propels the capsule type medical device C10 by
giving electric stimulation as needed to the body tissue such as
the stomach, small intestine, large intestine or other. In fact,
rapid changes of the photo images indicate that the capsule type
medical device C10 is moving too fast. Hence, the operator reduces
the number of times the current is sent to electrodes 6 to reduce
the speed of the capsule type medical device C10. On the other
hand, little change in the photo images indicates that the capsule
type medical device C10 is hardly moving. Hence, the operator
raises frequency of sending current to the electrodes 6, which
increases the moving speed of the capsule type medical device
C10.
When the capsule type medical device C10 is in the small intestine,
the radio transceiver unit 4 receives control signals sent from the
external device 100. Upon receiving the signals, the control unit 3
controls the amount of current to be sent to the electrodes 6 or
operation of motors M. The electrodes 6, upon receiving current,
give electric stimulation to and contract the body tissue
(intestine wall). With contraction of the body tissue, the capsule
type medical device C10 moves forward as if being pushed out.
Hence, the capsule type medical device C10 can move inside the
small intestine more accurately than by autonomic peristaltic
motion, enabling efficient observation inside the small intestine
with shorter observation time.
When the capsule type medical device C10 passes through the small
intestine and reaches the large intestine (see FIGS. 21(3), (4)),
the photographing element 2a takes pictures inside the large
intestine and sends the photo images to the external device 100
(see FIGS. 22(3), (4)). The position detection circuit 104a
confirms that the capsule type medical device C10 is in the large
intestine by comparing the photo images received and the setting
image, in a manner similar to above. Responding to this, the
control unit 104 drives the electrodes 6, gives electric
stimulation to the body tissue from the electrodes 6, and sends
signals through the radio transceiver unit 102. Upon receiving the
signals, the control unit 3 starts up the motors M and drives the
electrodes 6. At this time the electrodes 6 are not made to operate
at maximum capacity, unlike the case in the stomach, but the
flexible wires are unwound longer than the case in the small
intestine. This is because the large intestine has a larger lumen
organ than the small intestine, but a much smaller lumen organ than
the stomach. With this, electric stimulation is given to the body
tissue (intestine wall) in the large intestine with a larger lumen
organ than the small intestine while the electrodes 6 are
accurately attached to the body tissue. Hence, in a manner similar
to in the small intestine, efficient and stable observation inside
the large intestine is achieved with shorter observation time.
When the capsule type medical device C10 passes through the large
intestine and reaches the anus (near rectum) (see FIG. 21(5)), the
photographing element 2a takes picture inside the anus and sends
the photo images to the external device 100 (see FIG. 22(5)). The
position detection circuit 104a confirms that the capsule type
medical device C10 is in the anus (near rectum) by comparing the
photo images received and the setting image, in a manner similar to
above. Responding to this, the control unit 104 completely stores
the electrodes 6 and the flexible wires 7, and sends signals
through the radio transceiver unit 102 to stop electric stimulation
by the electrodes 6. Upon receiving the signals, the control unit 3
starts up the motors M and restores the original conditions by
completely storing the electrodes 6 and flexible wires 7 in the
wire storage units 21. This improves dischargibility of the capsule
type medical device C10 after completion of observation.
Or, it is possible to actively control discharge by allowing the
electrodes 6 to protrude slightly above the outer surface of the
capsule type medical device to give electric stimulation within the
rectum with desired timing for discharge (for example desire to go
to the bathroom). In this case, discharge of the capsule type
medical device C10 is achieved without fail when preparation for
discharge is completed in the bathroom.
Moreover, arrangement of a notification device inside the external
device 100 for sending positioning of the capsule type medical
device C10 at the anus (near rectum), thus indicating discharge
timing to the doctor and others, may improve usability of the
device.
Meanwhile, the doctors, and others diagnose the physical condition
of the patient based on the in-vivo information, namely photo
images, recorded in the recording unit 103 of the external device
100.
In the capsule type medical device C10, the motors M that are
controlled by the control unit 3 are used to drive rotation of the
rotation shafts 22r. Hence, unwinding and winding of the flexible
wires 7 are arbitrarily executed by the control of the control unit
3, enabling arbitrary change of the distance between the electrodes
6 at arbitrary locations. With this, even if the area of the lumen
organ changes by organ, it may be easily handled by changing the
length of the flexible wires 7, enabling accurate supply of
electric stimulation no matter where the location may be. Moreover,
the motors M only drive unwinding/winding of thin flexible wires,
and electric energy consumption is small. Thus, the motors M do not
become much burden on a capsule type medical device C10 that is
driven by batteries.
Hereafter, deformed examples of the capsule type medical device C10
in the aforementioned second embodiment will be shown. Here, each
structural element such as the photographing unit 2 (photo element
2a and light emitting element 2b), control unit 3, radio
transceiver unit 4 and battery 5 of the capsule type medical device
C10 is a common structural element provided in a similar manner in
each of the deformed examples of the capsule type medical device
below. Hence, in the following examples, presentation and detailed
description of these structural elements are omitted. Moreover,
other structural elements similar to those in the capsule type
medical device C10 are denoted with the same symbols and detailed
description of those is omitted.
FIG. 23A and FIG. 23B show a first deformed example. In the capsule
type medical device C11, one pair of electrodes is anchored
directly on the casing, and a weight is provided on the side where
the electrode is anchored inside the casing.
A wire storage unit 21 is formed in a recess at one location in the
rear section of the casing 16 and pushes the electrode 6 and the
flexible wire 7 in and out through hole unit 21h to the outside. On
the opposite side of the wire storage unit 21h across the diameter
at the rear side of the casing 16, a fixed electrode (electrode) 62
that makes a pair with the electrode 6 is attached on the outer
surface of the casing 16 as one body. The flexible wires 7 and
electrode 6 are connected to the control unit 3 inside the casing
16. On the opposite side of the electrode storage unit 21 across
the diameter within the casing 16, a weight G is provided. With
this, the side of the fixed electrode 62 can be made to face
downward always, hence the fixed electrode 62 is accurately made to
contact the mucous membrane or the like.
In the capsule type medical device C11, because the wire storage
unit 21 and motor M are one unit, the structure is simple, and
control of unwinding and winding of the flexible wire 7 is executed
easily and accurately.
Here, in this example, the weight G is provided to make certain
that the fixed electrode 62 contacts the mucous membrane or the
like, but the weight G may be omitted by changing the arrangement
of each part inside the casing 16 in such a manner that the center
of gravity shifts to a position on the side of the fixed electrode
62.
FIG. 24 shows a second deformed example. In the capsule type
medical device C12, a pair of electrodes is attached on the front
section of the aforementioned capsule type medical device C.
The base ends of front side the flexible wire 9 is supported at the
front side (the other edge side along the axis L) of the casing 16
but at the rear side of the transparent dome 1d. The front side
flexible wire 9 protrudes externally from the casing 16 in a manner
such that the wire moves away from the case outwardly and the
supports the front side electrode 8. In other words, the electrode
8 is provided through the flexible wire 7 at the front side of the
casing 16, separate from the photography unit 2. Hence, the
electrode 8 does not block photographing by the photography unit 2.
Here, the front side flexible wire 8 is provided on the same side
as the wire storage unit 21.
Moreover, on the external surface of transparent dome 1d, which is
on the opposite side from the front electrode 8 across the
diameter, namely on the same side as the fixed electrode 62, the
front side fixed electrode (the second electrode) 82 forming a pair
with the front electrode 8 is attached as one unit. This front
fixed electrode 82 is provided in a position further outside than a
field of vision V of the photographing element 2a so as not to
block the photographing by the photographing part 2. Here, the
front fixed electrode 82 may be a transparent electrode and may be
arranged inside the field of vision V. In this case, electrodes
with easier position and size for making contact with the body
tissue may be used.
The front flexible wire 9 and front fixed electrode 82 are
connected to the control unit 3 (represented in FIG. 2) inside the
casing 1. Here, the control unit 3 possesses a function as second
control device for controlling current to be sent to the front
electrode 8 and the front electrode 82 based on control signals
from the radio transceiver unit 4, independent of the control of
current to be sent to the electrode 6 and the fixed electrode
62.
Moreover, the weight G is provided on the opposite side of the
electrode storage unit 21 across the diameter inside the casing 16,
making the fixed electrode side constantly face downward. Hence,
accurate contact of the fixed electrode 62 and front fixed
electrode 82 with the mucous membrane or the like is achieved.
Here, in swallowing the capsule type medical device C12, it is
preferable to swallow backward to prevent the front electrode 8 and
front flexible wire from becoming obstacles.
In the capsule type medical device C12, in addition to the
electrode 6 and fixed electrode 62 that are provided on the rear
side of the casing 16, the front electrode 8 and front fixed
electrode 82 are provided on the front side with current to each
electrodes being controlled independently. For this reason, each of
the wire storage unit 21 and motor M is made to be one unit to make
the structure simple while achieving free movement of the device
inside the body tissue. In other words, by making the electrode 6
and fixed electrode 62 provided on the rear side of the casing 16
gives electric stimulation to the body tissue forward movement of
the capsule type medical device C12 is achieved. Conversely,
backward movement of the capsule type medical device C12 is
achieved by making the front electrode 8 and front fixed electrode
82 provided on the front side of the casing 16 give electric
stimulation to the body tissue. With this, the operator can move
the capsule type medical device C12 in the lumenal organ such as
the small intestine or large intestine, for example, forward or
backward as needed while watching the photo images, which improves
operation capability. Moreover, the operator can easily handle the
device without regard to direction, front side or rear side, of a
narrow lumenal organ, the capsule type medical device C12 enters
from. Furthermore, because forward and backward movement are both
available, any possible location in the lumenal organ may be
observed
Next, FIG. 25A and FIG. 25B show a third deformed example. In the
capsule type medical device C13, the wire storage unit and the
mechanism for unwinding and winding the flexible wires are
different from those of the aforementioned capsule type medical
device C10.
In the capsule type medical device C13, a wire storage unit 26 for
storing the flexible wires 7 and the electrodes 6 inside the casing
17 is formed. A wire storage unit 26 is formed at a location near
the rear section of the casing 17, namely inside the tapered
section, as a space and makes the electrodes 6 and the flexible
wires 7 appear and disappear externally through openings 26h. Each
of the openings 26h is formed in a position such that the openings
are mutually symmetrical about the axis L of the casing 17. Inside
the wire storage unit 26, a rotation table 26r with a substantially
disk shape is supported in such a manner that its axis of rotation
is substantially the same as axis L and it is free to rotate. The
base ends of the flexible wires 7 are connected respectively to two
locations on the outer circumference side of the rotation table 26r
that are symmetrical to each other relative to axis L. In other
words, current from the control unit 3 flows to the electrodes 6
through the rotation table 26r and flexible wires 7.
The rotation table 26r is connected to the motor (actuator) M2,
which is provided further rear than the wire storage unit 26.
Motion of the motor M2 is controlled by the control unit 3. The
rotation driving force from the motor M2 is transmitted to the
rotation table 26r. In other words, the motor M2 and rotation table
26r constitute the mechanism for unwinding/winding the flexible
wires 7. In the unwinding/winding mechanism with such a mechanism,
the motion of the motor M2 is controlled by external control
signals, and the electrodes 6 are put into operation at an
arbitrary location through unwinding of the flexible wires 7. Or,
the flexible wires 7 and electrodes 6 may be completely stored
inside the wire storage unit 26 through winding. Any motor/actuator
such as an electromagnetic motor, a super sound wave motor, a
static electric motor or the like is used as the motor M2.
In the capsule type medical device C13, because one motor M2 is
made to execute all the unwinding/winding of the pair of flexible
wires 7 and electrodes 6, the structure is simple and control of
unwinding/winding is easy and precise. Moreover, the limited space
in the casing 17 is utilized effectively because the wire storage
unit 26 and the motor M2 are provided inside the tapered section in
the vicinity of the rear section, which tends to become dead space
in the casing 17.
Here, in each of the embodiments above, a description is given
using an example in which the present invention is applied to a
wireless capsule type medical device. However, the present
invention may be applied to a wired capsule type medical device in
which electric power is supplied with a cord and the like. With
this, a battery to be mounted on the capsule type medical device is
unnecessary, or made to be smaller and low capacity. Moreover, the
cord for supplying electric power may be thin in most cases, which
minimizes discomfort and concern of the cord becoming an obstacle
inside the lumenal organ for a person being examined.
Moreover, in each of the embodiments above, a description is given
for a structure in which in-vivo information acquisition device for
acquiring in-vivo information such as images is provided. However,
in addition to such in-vivo information acquisition device, a
medication device for administering medicine at a desired part, a
treatment device for burning a diseased part, or an extraction
device for extracting bodily fluid and the like may be provided as
needed. Use of such a capsule type medical device enables
medication, treatment or sampling after acquisition of in-vivo
information. Hence, a series of different operations may be
executed inside the living body using only one capsule type medical
device.
The third embodiment of the present invention will be shown with
reference to FIGS. 26 through 40.
In this embodiment, an elastic expansion device forms the
interelectrode distance variation device. The capsule-type medical
device C14 shown in FIG. 26 is the basic configuration of the
capsule-type medical device of the present embodiment. This
capsule-type medical device C14 is provided with a capsule body
(device body or casing) 201, a balloon (elastic expansion part)
202, at least one pair of bipolar electrodes 203, wires 204, a
battery (power source) 5, and an expansion and contraction
mechanism unit (expansion device) 16. The balloon 202 is mounted on
at least one part of the capsule main body 201 and is capable of
expanding elastically. The electrodes 203 are mounted on the
balloon 202, and provide an electric stimulus to contractible
tissue (body tissue) in the living body cavity.
The capsule main body 201 is provided, inside a casing 211, with a
photographing unit (living in-vivo information acquisition device)
212 that obtains living in-vivo information inside the living body
cavity, a control unit (control device) 213, a wireless transceiver
(communication device) 214 and a battery (power source) 205, and
has the function of a capsule-type endoscope. In addition, inside
the casing 211 an expansion and contraction mechanism unit 216 is
also provided which causes the balloon 202 to expand and
contract.
The casing 211 is a capsule with an oval shape when viewed from the
side, and is formed of plastic or the like so as to seal the
inside. In the front of the casing 211 (to the right in the
diagram), an observation window (unrepresented in FIG. 26) composed
of a transparent material formed into a dome shape is provided. On
the inside of this observation window, that is to say to the front
of the capsule main body 201, the photographing unit 212, which
obtains living in-vivo information inside the living body cavity,
is housed. The photographing unit 212 is equipped with a
photographing element unit 212a used to photograph the various
areas inside the living body cavity and obtain images, and a
light-emitting element 212b in order to illuminate the field of
vision of the photographing element unit 212a by shining an
illuminating light, and living in-vivo information is obtained by
obtaining photo images inside the living body cavity. The imaging
element 212a is composed of a lens and a CCD (charge coupled
device) or the like. The light-emitting element 212b is composed of
an EL (electroluminescent) element, an LED (light-emitting diode)
or the like. In addition to the photographing unit 212, various
sensors such as a pH sensor, a hemoglobin sensor, a special light
reaction sensor or the like may be provided as appropriate inside
the observation window as living in-vivo information acquisition
device.
The radio transceiver unit 214 is provided with an unrepresented
transceiver unit main body and a transceiver antenna (omitted from
diagram) that transmits and receives radio waves. The radio
transceiver unit 214 wirelessly transmits to the below-shown
external device 300 the in-vivo information, that is to say the
photo images photographed by the photographing unit 212. In
addition, the wireless transceiver unit 214 wirelessly receives
various control signals (instructions) wirelessly transmitted from
the external device 300, and conveys them to the control unit
213.
The control unit 213 has a function for comprehensively controlling
the actions of the various units of the capsule-type medical device
C14 on the basis of the control signals (instructions) from the
radio transceiver unit 214. Concretely, this unit performs radio
transceiver control (control of the actions of the radio
transceiver unit 214), photo and illumination control (control of
the actions of the photographing unit 212) and expansion and
contraction control of the balloon 202 (control of the actions of
the expansion and contraction mechanism unit 216). In addition, in
the control unit 213 is provided a square wave (pulse) generating
circuit 213a for sending an electric current to the electrodes 203
from the battery 205 via the wires 204. In other words, the control
unit 213 has the function of a control device for controlling the
electric current flowing to the electrodes 203, as shown below.
Included in the square wave generating circuit 213a is a limiter
function that ensures that electric current exceeding a set value
does not flow to the electrode 203.
In FIG. 26, the square wave generating circuit 213a is provided in
an integrated manner with the control circuit 13, but this circuit
may instead be provided in an integrated manner with the battery
205.
The balloon 202 is furnished in the capsule main body 201 so as to
cover at least a portion of the outer surface of the casing 211.
This balloon 202 is composed of an elastic film made from elastic
material exhibiting elasticity, such as flexible rubber, and
expands and contracts due to the expansion and contraction
mechanism unit 216 provided inside the casing 211. The expansion
and contraction mechanism unit 216 causes the balloon 202 to expand
by supplying a fluid such as air or a foaming agent into the
balloon 202, and causes the balloon 202 to contract by sucking out
the fluid from inside the balloon 202. The balloon 202 is
substantially in close contact with the outer surface of the casing
211 when contracted so that the capsule main body 201 is easy to
insert into the living body cavity via the mouth or anus.
In FIG. 26, the front and back of the capsule main body 201 are
exposed, the balloon 202 covers the capsule main body 201 so as to
cover the outer circumference in the middle, and the balloon 202 is
anchored to the capsule main body 201 in a roughly ring shape at
the two anchoring units 220 in the front and back of the capsule
main body 201. However, it would also be fine for only the front of
the capsule main body 201 where the observation window is provided
to be exposed, and for practically the entire surface behind this
to be covered by the balloon 202. In this case, the balloon 202 is
anchored to the capsule main body 201 at the one anchoring unit 220
provided behind the observation window at the front of the capsule
main body 201.
On the outer surface of the balloon 202, at least one pair of
bipolar electrodes 203 is attached. These electrodes 203 make
contact with the inner wall of the small intestines and large
intestines, that is to say contractible tissue, and give an
electric stimulus to this contractible tissue. The shape of the
electrodes 203 is roughly hemispherical or roughly planar so as to
not hinder the forward motion of the capsule-type medical device
C14. In this way, the at least one pair of electrodes 203 is
provided in an integrated manner with the balloon 202, so the
distance between the pair of electrodes 203 changes in accordance
with expansion and contraction of the balloon 202. Consequently,
even if the diameter of the lumen changes, it is possible to give
electric stimulus precisely to contractible tissue inside the
lumenal organ. These electrodes 203 are preferably made from metal
having high compatibility with the living body (such as stainless
steel, platinum, titanium or the like), or a conductive material
such as conductive rubber or the like as shown below.
In FIG. 26, a total of two pairs of electrodes 203 are provided,
one pair each on the front side (the right side in the diagram) and
the back side (the left side in the diagram) but the number of
electrodes installed and the installation position of such can be
appropriately altered.
The wires 204 are composed at least in part of a conductive
material such as metal or the like that is flexible. The base ends
of the wires 204 are connected to the square wave generating
circuit 213a in the casing 211, and the tips are connected to the
electrodes 203. That is to say, the electrodes 203 are connected
mechanically and electrically to the capsule main body 201 in which
the battery 205 is housed. Because flexible wires 204 are thus
used, the wire 204 accommodates contraction of the balloon 202 in a
folded state, and when the balloon 202 expands the wire 204
elongates. Accordingly, it is possible to constantly supply
electric power to the electrodes 203 from the square wave
generating circuit 213a in the control unit 213.
The outer diameter of the capsule-type medical device C14 composed
as shown above is around 15 mm when the balloon 202 is contracted
so that it is easy for the device to pass through the digestive
tract and anus. In addition, the outer diameter of the capsule-type
medical device C14 is around 40 mm when the balloon 202 is expanded
to its maximum so that the electrodes 203 suitably contact the body
tissue when the device passes through the large intestines.
The external device 300 controls the capsule-type medical device
C14 from outside the living body. As shown in FIG. 26, the external
device 300 is equipped with a radio transceiver unit (transmission
unit and detection unit) 302 for sending and receiving information
to and from the capsule-type medical device C14, a recording unit
303 such as memory or the like for accumulating the above-shown
living in-vivo information, that is to say the photo images, a
control unit 304 that controls the various units and a battery 305
that supplies electric power to the various units, all inside a
device main body 301.
The device main body 301 is formed into a box shape by plastic or a
metal such as aluminum, and can be mounted on the subject's body
via the subject's belt. Through this, the subject can always have
the external device 300 mounted on their body.
The radio transceiver unit 302, similar to the radio transceiver
unit 4 of the capsule-type medical device C14, is provided with an
unrepresented transceiver unit main body and transceiver antennas
for sending and receiving radio waves (a transmission antenna and a
reception antenna). The radio transceiver unit 302 receives photo
images that are living in-vivo information transmitted wirelessly
from the capsule-type medical device C14, and conveys such to the
control unit 304.
The control unit 304 sends control signals in accordance with the
body tissue surrounding the capsule-type medical device C14
positioned in the living body (e.g., the stomach, small intestine
or large intestine) to the capsule-type medical device C14 via the
radio transceiver unit 302. In addition, the control unit 304
records photo images that have been received in the recording unit
303 whenever required, after performing prescribed processes such
as image processing or the like.
Now the casing where a subject's body cavity is observed and
studied using the capsule-type medical device C14 composed as shown
above.
First, the subject attaches the external device 304 to their belly
or elsewhere via a belt or the like. Then, the capsule-type medical
device C14 is introduced into the living body cavity by the
capsule-type medical device C14 being inserted into the mouth
(swallowed). At the time of this oral insertion, the balloon 202 is
contracted so as not to become an obstruction. In addition to
photographing of various parts inside the living body cavity
through the photographing element unit 212a while moving down the
alimentary canal, the photo images are wirelessly transmitted to
the external device 300 from the radio transceiver unit 214. On the
other hand, the external device 300 receives the photo images via
the radio transceiver unit 302, performs image processing or the
like on the photo images via the control unit 304 and records the
images whenever required in the recording unit 303. The control
unit 304 sends to the capsule-type medical device C14 control
signals used to control the capsule-type medical device C14 via the
radio transceiver unit 302 whenever required.
When the capsule-type medical device C14 has passed through the
stomach and duodenum and reached the small intestine, the control
unit 213 causes the balloon 202 to expand through a control signal
from the external device 300, and causes the capsule-type medical
device C14 to propel by giving an appropriate electric stimulus to
the inner wall of the small intestine. In the small intestine, the
balloon 202 is expanded to around 5-15 mm and the outer diameter of
the capsule-type medical device C14 (the outer diameter of the
capsule main body 201 together with the balloon 202) becomes around
20-30 mm so that the electrodes suitably contact the inner wall of
the small intestine, In order to give an electric stimulus to the
contractible tissue of the small intestine and cause it to
contract, and to use this contracting force as propulsion for the
capsule-type medical device C14, in general several milliwatts to
several dozen milliwatts are necessary. Consequently, the square
wave generating circuit 213a causes a square wave electric current
of several milliwatts to several dozen milliwatts to flow to the
electrodes 203 in pulses with a prescribed period. Specifically,
the frequency at this time is several Hz to several dozen Hz, and
the pulse width is set at several milliseconds to several dozen
milliseconds. It would also be fine to use as this pulse signal a
signal modulated by a high-frequency signal of several kilohertz to
several dozen kilohertz. Such a modulated wave signal outputs a
pulse of several kilohertz to several hundred kilohertz with a
period of several hertz to several dozen hertz.
The waveform of the pulse wave may be square or sinusoidal. In
addition, the square wave may be a waveform that only outputs in
either positive or negative normally, and as shown in FIG. 27A, may
be a waveform in which the output is reversed and is output on both
the negative and positive sides (two-sided amplitude). Furthermore,
the sinusoidal waveform may be a waveform with one side rectified,
as is shown in FIG. 27B. The square wave generating circuit 213
outputs signals with a waveform that combines the various
above-shown waveforms, and provides electric stimulation to the
body tissue.
When this kind of electric stimulation is provided to the inner
wall of the small intestine, the small intestine where the stimulus
was given contracts and the capsule-type medical device C14 propels
in the forward direction by being squeezed down the contracted
small intestine. At this time, it is possible to accurately absorb
changes in the diameter of the small intestine because the balloon
202 and the wire 204 elastically deform in accordance with the
contraction of the small intestine. Through this, it is possible to
move through the small intestine by speeding up the peristaltic
movement of the small intestine, and it is possible to efficiently
observe and study the inside of the small intestine while
shortening the time needed for observation. When the capsule-type
medical device C14 has reached its target location, the
capsule-type medical device C14 can be stopped at the target
location by stopping the electric stimulation. At this time, the
balloon 202 may be expanded after halting electric stimulation and
the contact pressure with the small intestine increased so as to
more accurately stop the capsule-type medical device C14.
In this manner, the capsule-type medical device C14 can next pass
through the large intestine as well following the gist of the above
discussion. When passing through the large intestine, the balloon
202 is caused to expand to 5-25 mm and the outer diameter of the
capsule-type medical device C14 becomes .phi.20-40 mm so that the
electrodes accurately contact the inner wall of the large
intestine. As the capsule-type medical device C14 approaches the
anus, the balloon 202 is caused to contract similar to when the
device was orally inserted, so that the outer diameter of the
capsule-type medical device C14 becomes smaller and the device can
be expelled from the anus.
Following this, the doctor performs a diagnosis of the health
condition of the subject based on the photo images that are living
in-vivo information recorded in the recording unit 303 of the
external device 300.
In this capsule-type medical device C14, it is possible to cause
the electrodes 203 to accurately contact the inner wall of the
digestive tract having differing diameters by causing the balloon
202 to expand at the desired position. In addition, because the
wires 204 are flexible, they can cope with both expansion and
contraction of the balloon 202 and can provide a stable electric
stimulus with practically no inconveniences such as disconnections
or the like occurring. In addition, by stopping the electric
stimulus at the target location or, after stopping the electric
stimulus, causing the balloon 202 to expand, the capsule-type
medical device C14 can be stopped in the location, the location can
be observed and a detailed study can be conducted through the
various sensors. Furthermore, by causing the balloon 202 to
contract on the expulsion side after completion of observations and
studies, it is possible to cause the device to move swiftly and
expel the device to the outside of the living body in a short
time.
Next, variations of the above-shown capsule-type medical device C14
of the third embodiment will be shown. Constituent elements in
common with the various constituent elements of the capsule-type
medical device C14 are labeled with the same reference numbers and
detailed explanations of such are omitted here. In addition, in the
various diagrams referenced below, there are cases when diagrams of
the wires 204 are suitably omitted, and in these cases, the various
electrodes 203 are connected electrically and mechanically to the
capsule main body 201 via the wires, similar to in the above-shown
capsule-type medical device C14.
FIGS. 28A and 28B show the first variation.
In this capsule-type medical device C15, the balloon 202A is
removably mounted on the capsule main body 201A via a mounting unit
20A. In addition, the wires 204 are removably connected to the
capsule main body 201A via a connector 204C.
The capsule main body 201 is composed similarly to the capsule main
body 201 in the above-shown capsule-type medical device C14 with
the exception of the fact that the casing 211A is provided. The
casing 211A differs from the above-shown casing 211 in that it is
provided with a groove 211g so that attaching and removing the
balloon 202A is easy and in that a female-side connector 242 is
formed on the back surface. A reference number 211d indicates an
observation window.
In the groove 211g formed in the casing 211A, a mounting unit 20A
is formed by a removable protrusion unit 2t engaging removably with
the groove 211g formed in the balloon 202A. In addition, a
female-side connector 241 comprises a connector 204C in a pair with
the male-side connector 41 provided on the base end of the wire
204, and through this connector 204C, the wire 204 and casing 211A
are removably connected. Furthermore, the electrodes 203 are
provided in an integrated manner on the outside of the balloon 202,
and are composed of conductive rubber made from conductive silicone
rubber or conductive nylon or the like.
Because the electrodes 203 are thus composed of conductive rubber,
when the balloon 202A expands, the electrodes 203 on the balloon
202A can similarly elongate and the balloon 202 can be expanded
more uniformly.
In addition, because the capsule main body 201A, the balloon 202A,
the electrodes 203 and the wires 204 are removably mounted, the
balloon 202A, the electrodes 203 and the wires 204 can be easily
replaced with optimum items in accordance with the usage conditions
of the capsule-type medical device C15. Furthermore, the relatively
expensive capsule main body 201A can be repeatedly used, while the
relatively inexpensive balloon 202A, electrodes 203 and wire 204
can be easily disposed of after each use.
FIGS. 29A and 29B show a second variation.
This capsule-type medical device C16a is an example with a hard
member provided in the balloon. This hard member is formed on the
thick part of a portion of the above-shown balloon 202 and is
harder than the other parts.
In the capsule-type medical device C16a shown in FIGS. 29A and 29B,
the balloon 202B1 is attached to the capsule main body 201 via an
anchoring unit 220 so as to cover the side of the capsule main body
201 to the rear of the observation window 211d. In this balloon
202B1, a hard member 221a is formed so as to form a ring on the
back side, and numerous electrodes 203 are attached around the
circumference of this hard member 221a.
As shown above, the balloon 202 is formed of stretchable materials
such as flexible rubber, and when the electrodes 203 are formed of
gold or other materials that do not substantially stretch, the
elongation ratio of the two differs significantly. In other words,
mounting and maintenance of the electrodes 203 onto the balloon
becomes difficult, and the arrangement does not withstand prolonged
usage. Consequently, by forming a thick, hard unit on the balloon
at least in the area when the electrodes 203 are mounted, it is
possible to reduce the difference in elongation ratio between the
two, making it possible to more easily mount and maintain the
electrodes 203 on the balloon.
FIGS. 30 through 32 show a third variation.
These capsule-type medical devices C16b, C16c and C16d are
variations of the capsule-type medical device C16a, with the
position where the hard member is formed on the balloon
differing.
In the capsule-type medical device C16b shown in FIG. 30, a balloon
202B2 is attached to the capsule main body 201 by an anchoring unit
220 so as to cover the side of the capsule main body 201 to the
rear of the observation window 211d. On both the front and back
edges of this balloon 202B2, a thick, hard member 221b is formed,
and numerous electrodes 203 are attached around the outside
circumference of this hard member 221b.
In addition, in the capsule-type medical device C16c shown in FIG.
31, a balloon 202B3 is attached to the capsule main body 201 by an
anchoring unit 220 so as to cover the side of the capsule main body
201 to the rear of the observation window 211d. A thick, hard
member 221c is formed near the fringe of the electrodes 203 on the
top and bottom of this balloon 202B3 and in a central area a
prescribed distance from the top and bottom electrodes 203.
Furthermore, in the capsule-type medical device C16d shown in FIG.
32, the balloon 202B4 is attached to the capsule main body 201 by
anchoring units 220 at two locations in the front and back so as to
cover the center part of the capsule main body 201 while exposing
both the front and back edges. On the outer perimeter of this
balloon 202B4, a thick, hard member 221d is formed in a spiral
shape, and multiple electrodes 203 are attached to the outer
perimeter of this hard member 221d.
In this manner, the shape and positioning of the hard member can be
altered as appropriate in accordance with the number and
arrangement of electrodes 203 mounted on the balloon.
FIGS. 33 and 34 show a fourth variation.
These capsule-type medical devices C16e and C16f are other
variations of the capsule-type medical device C16a, and illustrate
an example in which a separate hard member is provided on the
above-shown balloon 202 and is harder than other areas.
In the capsule-type medical device C16e shown in FIG. 33, the
balloon 202B5 is attached to the capsule main body 201 by the
anchoring unit 220 so as to cover the capsule main body 201 to the
back side of the observation window 211d. In this balloon 202B5,
multiple hard members 221e are provided around the perimeter on the
back side. These hard members 221e are formed by coating the outer
surface of the above-shown balloon 202 with an adhesive and
hardening this. The electrodes 203 are attached to the various hard
members 221e.
In addition, in the capsule-type medical device C16f shown in FIGS.
34A and 34B, a balloon 202B6 is attached to the capsule main body
201 by the anchoring unit 220 so as to cover the capsule main body
201 to the back side of the observation window 211d. Attached to
this balloon 202B6 are electrodes provided in an integrated manner
member with hard members 221f, which are composed of hard rubber
that is harder than the balloon 202 and are provided on the outer
perimeter of the back side of the above-shown balloon 202.
In this manner, hard members made of a material separate from the
balloon 202 are attached after the fact, and consequently the
composition of the balloon 202B5 and the balloon 202B6 is made
simple and manufacturing is easy.
FIG. 35 shows a fifth variation.
The capsule-type medical device C17 is an example in which the
lengthwise cross-sectional shape (the cross-sectional shape when
viewed from the front) is deformed when the balloon is
expanded.
The balloon 202C in the capsule-type medical device C17 shown in
FIG. 35 is expanded such that the lengthwise cross-section has a
star shape. Electrodes 203 are provided at the tips of this
star-shaped balloon 202C. When such a star-shaped balloon 202C is
expanded, only the tips make contact with the inner wall of the
lumenal organ (here represented by the small intestine I). Between
each of these tips, the balloon 202C has indentations.
Consequently, between these indentations and the small intestine I,
spaces Ih are formed along the inside of the small intestine I
running forward and backward along the capsule-type medical device
C17.
Because these spaces Ih are formed, the inside of the small
intestine I is not blocked even when the balloon 202C is expanded.
Consequently, fluids such as digested materials that are present in
the small intestine I can flow suitably along the length of the
capsule-type medical device C17.
The capsule-type medical device C18 shown in FIG. 36, the
capsule-type medical device C19 shown in FIG. 37 and the
capsule-type medical device C20 shown in FIG. 38 are all variations
of this capsule-type medical device C17. In each of these
variations, the lengthwise cross-sectional shape of the
capsule-type medical device is altered. These lengthwise
cross-sectional shapes when the balloon is expanded can be
appropriately altered in accordance with the objective or
conditions of the examination.
FIG. 36 shows a sixth variation.
The balloon 202D in this capsule-type medical device C18 is
anchored by anchoring units 220B formed in two locations (top and
bottom locations in the drawing) that are at symmetrical positions
on the outer perimeter of the capsule main body 201, and when the
balloon expands, expansion is roughly symmetrical in the left and
right directions. Consequently, spaces Ih are formed between the
anchoring units 220B and the small intestine I that pass from front
to back along the capsule-type medical device C18 in the lumenal
organ.
FIG. 37 shows a seventh variation.
The balloon 202E in this capsule-type medical device C19 expands so
that the lengthwise cross-section has an elliptical shape.
Consequently, spaces Ih are formed between the long sides of the
balloon 202E (the top and bottom in the drawing) and the small
intestine I.
This capsule-type medical device C19 is provided with a capsule
main body 201B and a power source unit (power source) 205A. The
capsule main body 201B here is the above-shown capsule main body
201B from which the battery and square wave generating circuit for
applying an electric stimulus to the electrodes 203 are omitted. In
addition, in the power source unit 205A, the battery and square
wave generating circuit for applying an electric stimulus to the
electrodes 203 are incorporated in an integrated manner. The
operation of this power source unit 205A is controlled by control
signals received directly from the external device 300 or via a
control unit 213 (omitted from the drawing) inside the capsule main
body 201B.
In this manner, the power source and square wave generating circuit
for applying electric stimuli are made of separate materials from
the capsule main body 201B, so the capsule main body 201B has a
simple construction. In addition, the battery 205 (omitted from the
drawing) inside the capsule main body 201B is not used for applying
electric stimuli, so the battery 205 can be used for a long
time.
FIG. 38 shows an eighth variation.
The balloon 202F in this capsule-type medical device C20 is
provided with pass-through holes 222 that pass through the
capsule-type medical device C20 from front to back. Consequently,
the same function as of the above-shown spaces Ih is secured with
these pass-through holes 222.
FIGS. 39A through 39D show a ninth variation.
The structure of the expansion and contraction mechanism of this
capsule-type medical device C21 differs from that of the
above-shown capsule-type medical device C14. In the capsule main
body 201C of this capsule-type medical device C21, the various
constituent elements of the above-shown capsule main body 201 are
provided in an integrated manner in the casing 211B. Furthermore,
in the casing 211B, a storage chamber 261, a guide hole 262a, a
guide hole 262b and a screw hole 263 are formed, and a moving
member 264 is interlocked into this screw hole 263. Through these
various constituent elements, a function corresponding to the
above-shown expansion and contraction mechanism unit 216 is
secured.
As shown in FIGS. 39A through 39C, in the storage chamber 261
provided in the capsule main body 201C, a pressurized gas g is
stored from a hole passing through from the outside, and after this
is stored, this hole is blocked by a rubber cap 261s. As shown
below, a foaming agent may be used in place of this pressurized gas
g. In addition, this storage chamber 261 is connected to the screw
hole 263 that enables rotational movement of the moving member 264
via the guide hole 262a, and this screw hole 263 is further linked
to the outside of the capsule-type medical device C21 via the screw
hole 262b. The back edge of this screw hole 263 opens to the
outside of the capsule-type medical device C21.
In addition, the back edge side of the capsule main body 201C is
covered by a balloon 202, and the front edge side of this balloon
202 is anchored in an airtight manner by belt-like anchoring
members 20 near the center of the capsule main body 201B. On the
back edge side of the balloon 202, electrodes 203 are anchored, and
these are connected electrically and mechanically to the capsule
main body 201C by flexible wires 204.
The moving member 264 is composed of a permanent magnet 264m that
is bar-shaped, for instance, and magnetized into a north pole and a
south pole in the direction orthogonal to the lengthwise direction
thereof, and elastic rubber 264g in the shape of a male screw that
covers this permanent magnet 264.
An explanation will now be given for the case of observing and
studying the inside of the living body cavity of a subject using
the capsule-type medical device C21 composed as shown above.
First, the subject attaches the external device 300 and the
below-shown rotating magnetic field generating device to their
belly or elsewhere via a belt or the like. Then, the capsule-type
medical device C21 is introduced into the living body cavity by the
capsule-type medical device C21 being inserted from the mouth. When
the capsule-type medical device C21 is introduced into the living
body cavity, the balloon is contracted, as shown in FIG. 39A.
Until the capsule-type medical device C21 has propelled to the
duodenum and reached the position to be studied selectively by the
various sensors inside the observation window 211d, a rotating
magnetic field is imposed by an unrepresented rotating magnetic
field generating device placed outside the living body. Through
this, the moving member 264 is caused to rotate along the screw
hole 263 and caused to move to the front of the casing.
When the moving member 264 moves to the front of the casing, the
storage chamber 261 is connected to the balloon 202 via the guide
hole 262a and the screw hole 263, as shown in FIG. 39B. Through
this, the pressurized gas g flows into the balloon 202 as indicated
by the arrow, causing the balloon 202 to expand. A foaming agent
may be used in place of the pressurized gas g. In this case, it is
preferable to coat the inside of the balloon 202 with a small
quantity of water for a reaction.
When the balloon 202 thus expands, the electrodes 203 on the
balloon 202 make contact with the inner wall of the digestive tract
(lumenal organ) near this position. In addition, by sending a
square wave current of several milliamps to the electrodes 203 in
pulses with a certain period, contraction of the inner wall of the
digestive tract in that area is caused through electric stimulus,
and by converting this contraction force into a propulsion force,
the device is propelled to the target position. Following this,
when the target position has been reached, the electric current is
stopped, the device is caused to remain at this position and
detection is accomplished through the various sensors. Following
this, after a time sufficient for detection to be completed by the
various sensors, electric current is against caused to flow to the
electrodes 203, and through the resulting contraction force caused
by the electric stimulus, the device is propelled to the anus.
Furthermore, immediately before the anus, a rotating electric field
is imposed and the moving member 264 is caused to move to the front
edge side, and through this the inside of the balloon 202 is
connected to the outside of the capsule-type medical device C21 via
the screw hole 263 and the guide hole 262b. That is to say, the
pressurized gas that expanded the balloon 202 is ejected to the
outside and the balloon 202 contracts as shown in FIG. 39C.
Following this, the capsule-type medical device C21 is easily
expelled from the living body through the anus.
Because the expansion and contraction mechanism unit has this kind
of composition, expansion and contraction of the balloon 202 can be
accomplished more easily and accurately.
Next, FIGS. 40A through 40C show a tenth variation.
The balloon 202H of this capsule-type medical device C22 differs
from the above-shown balloon 202 and is composed of a material that
substantially does not expand or contract elastically. As a
concrete example of such materials, a thin Teflon (registered
trademark) film composed of PFA
(tetrafluoroethylene-perfluoro(alkoxy vinyl ether) copolymer) or
PTFE (polytetrafluoroethylene) or the like is suitable. In
addition, the wire 204 is printed in an integrated manner on a
flexible printed circuit board 204F, and this flexible printed
circuit board 204F is pasted on the inside surface of the balloon
202H.
When this capsule-type medical device C22 is inserted orally, the
balloon 202H is wound around the capsule main body 1 and is stopped
by a band 223 composed of starch, oblate or the like, as shown in
FIG. 40A. When the device reaches the stomach in this state, the
band 223 is dissolved and the balloon 202H can expand. After this,
the balloon 202H is caused to expand and the capsule-type medical
device C22 is caused to propel appropriately while applying an
electric stimulus to the inner wall of the lumenal organ by means
of the electrodes 203.
Because this balloon 202H does not substantially expand or contract
elastically, it does not expand beyond a predetermined maximum
outer diameter. Consequently, the length of the wire 204 is set in
accordance with the maximum expansion of the balloon 202H, and can
be pasted inside the balloon 202H in an integrated manner with the
flexible printed circuit board 204F. Consequently, there is
practically no concern of disconnection by repeated use of the wire
204, so the device can withstand more prolonged usage.
FIGS. 41A and 41B show an eleventh variation. In this capsule-type
medical device C24, the capsule main body 201D and the balloon 2021
are linked by a shape-remembering coil (expansion device) 216c.
In the capsule main body 201D, the expansion and contraction
mechanism unit 216 is omitted from the above-shown capsule main
body 201. In addition, the balloon 202I has the same material as
the above-shown balloon 202, but is shaped so as to protrude
further to the back from the back edge side of the capsule main
body 201D when contracted. A predetermined volume of a fluid
(water, air or the like) is sealed inside this balloon 202I. In
addition, a shape-remembering coil 216c made from a
shape-remembering alloy extends from the back edge of the capsule
main body 201D, and the tip of this is connected to the back edge
of the balloon 202I by a connecting piece 16d. This
shape-remembering coil 216c has a shape-remembering property such
that it extends to a long shape when the surrounding temperature is
lower than body temperature and shrinks into a coil shape when the
surrounding temperature reaches body temperature.
The subject inserts the capsule-type medical device C24 in the
state shown in FIG. 41A into the living body cavity orally. In the
living body cavity, the surrounding temperature of the capsule-type
medical device C24 becomes about the same as body temperature, so
the shape-remembering coil 216c shrinks. As a result, the balloon
202I deforms and expands sideways, as shown in FIG. 41B, so that
the electrodes 203 on the balloon 202I make contact with the inner
wall of the lumenal organ.
In this manner, the balloon is expanded and contracted using the
shape-remembering coil 216c and hence it is possible to omit the
expansion and contraction mechanism unit from the capsule main
body, thereby making the composition thereof simpler.
In addition to setting the shape-remembering temperature of the
shape-remembering coil 216c higher than body temperature, it is
also possible to have a composition that can expand or contract the
balloon 202I at an arbitrary position by providing a heater or the
like that is controllable by the control unit 213 (omitted from the
drawings).
FIGS. 42A and 42B show a twelfth variation.
This capsule-type medical device C25 is a variation of the
above-shown capsule-type medical device C24. In place of the
above-shown balloon 202, an elastic expansion unit 202J made from
flexible rubber (an elastomer) having high elasticity is provided
on the above-shown capsule main body 201D. Wires 204 (omitted from
the drawings) are stored inside the elastomer in a water-tight
condition.
When this capsule-type medical device C25 is inserted orally, the
elastic expansion unit 202J is folded up so that the outer diameter
is small and is in a reduced-diameter state stored inside a capsule
224 made from starch, oblate or the like. When it reaches the
stomach in this state, the capsule 224 dissolves, so the elastic
expansion unit 202J expands elastically to a wide-diameter state.
Following this, the capsule-type medical device C25 is propelled
suitably while applying an electric stimulus to the inner wall of
the lumenal organ via electrodes 203. Because this elastic
expansion unit 202 has high elasticity, deformation is also easy.
Consequently, it can elastically deform when expelled from the anus
so that it can be easily expelled.
Because the device is equipped with this kind of elastic expansion
unit 202J, the expansion and contraction mechanism unit is omitted
from the capsule main body so that the composition thereof becomes
simpler.
A fourth embodiment of the present invention will be shown with
reference to FIGS. 43A through 43C. In this embodiment, constituent
elements in common with the constituent elements in the above-shown
third embodiment are labeled with the same reference numbers and
detailed explanation of such is omitted.
FIG. 43A shows the composition of the front edge side of the
endoscope device (capsule-type medical device) of this embodiment.
FIGS. 43B and 43C show the structure near an insertion opening of
the capsule-type medical device of this embodiment. Furthermore,
FIGS. 44A and 44B show the state of the endoscope device composed
of the capsule-type medical device after being released inside the
lumenal organ of a digestive organ such as the small intestine.
As is shown in FIGS. 43A through 43C, the endoscope device
(capsule-type medical device) S1 is provided with a capsule-type
medical device C26, a hollow tube 206 that can be freely attached
or removed from this capsule-type medical device C26, and an
endoscope 207 that is insertable into this tube 206. The
capsule-type medical device C26 is such that the expansion and
contraction mechanism unit 216 is omitted from the capsule-type
medical device C1 in the above-shown third embodiment.
The capsule-type medical device C26 is provided, in an observation
window at the tip of the capsule main body 201E, with a
light-emitting device unit 212b such as a white LED or the like and
a photographing element unit 212a composed of an optical system
such as an object lens and a solid-state photographing element such
as a CCD or CMOS imager, and in addition, on the side surface to
the back side thereof, a balloon 202K made from an elastic material
such as silicone rubber or latex rubber or the like the entire
circumference of which is easily expandable is attached to an
anchoring unit 220 by an anchoring ring or the like, and
additionally, on the back edge an injection opening 217a is
provided in order to supply a fluid to the inside of the balloon
202K (strictly, the space between the balloon 202K and the capsule
main body 201E). This injection opening 217a is connected to the
inside of the balloon 202K via a fluid channel 217. A tube 206 can
be freely attached or removed from this injection opening 217a in
order to supply a fluid to the balloon 202K. The front edge of the
tube 206 is a needle-shaped narrow-diameter unit 206 that can be
easily attached to the injection opening 217a. In addition, on the
unrepresented close side, there is a close-side opening hardware to
which a fluid injection tool such as a syringe can be freely
connected. Furthermore, by supplying fluid from this injection
opening 217a, fluid is injected into the balloon 202K via the fluid
channel 17, so that this balloon 202K can expand to the degree
(around 20-30 mm) that it can be in close contact with at least the
lumenal organ in the small intestine I.
The injection opening 217a provided at the back edge of the capsule
main body 201 has an elastic valve structure like the air valve on
a soft tennis ball so that after the balloon 202K has swelled, the
balloon 202K is sealed even if the tube 206 is removed. In
addition, a battery 205 is placed inside the capsule main body 201E
as a power source, and on the side of the back edge surface of the
balloon 202K, a pair of bipolar electrodes 203 are anchored, and
the electrodes 203 and the battery 205 are electrically and
mechanically connected via flexible ribbon-shaped wires 204.
The endoscope 207 is provided with a channel 271 along the axial
direction of a long and narrow insertion unit 270. On the other
hand, the tube 206 has a length longer than the length of this
channel 271, with an outer diameter that enables the channel 271 to
be smoothly inserted or removed, and a fluid such as air or water
can be supplied to the front edge from the base end of the tube
206.
As shown in FIG. 43B, a rubber cap 217v exhibiting elasticity is
attached in the injection opening 217a. A narrow channel 2171
formed in advance in this rubber cap 217v is in a blocked state
when a needle-shaped narrow-diameter unit 206t on the front edge of
the tube 206 is not penetrating it. In this case, the back edge of
this channel 217l has a mark so that the insertion position is
understood and an indentation 217u in order to allow easy insertion
of the needle-shaped narrow-diameter unit 206t.
As shown in FIG. 43C, when the needle-shaped narrow-diameter unit
206t is inserted into the injection opening 217a, the needle-shaped
narrow-diameter unit 206t penetrates the channel 217l. By injecting
a fluid such as a liquid or gas from the needle-shaped
narrow-diameter unit 206t in this state, it is possible to expand
the balloon 202K on the outside that comprises the fluid storage
unit, as shown in FIGS. 44A and 44B. With the tube 206 attached to
the injection opening 217a of the capsule main body 201E, when the
base end of the tube 206 is inserted from the tip of the channel
271, the base end of the tube 206 sticks out from the base end of
the channel 271 (omitted from drawings).
By applying a pulling force to the base end of the protruding tube
206 to the extent that the tube 206 does not fall out, or by
suction on the back edge of the capsule-type medical device C26
through the channel 271, the capsule-type medical device C26 can be
removably anchored to the tip of the endoscope 207, as shown in
FIG. 43A. When the capsule-type medical device C26 is anchored by
means of suction, an adsorption agent 7a composed of elastic rubber
or the like may be added between the capsule-type medical device
C26 and the tip of the endoscope 207 in order to increase the
adsorption function.
In order to assist releasing of the capsule-type medical device
C26, the balloon 202K may be expanded by inserting a grabbing tool
272F having a grabbing function into a second channel 272 provided
in the endoscope 207 and the holding unit at the tip of this
grabbing tool 272F grasping a grasping-use protrusion 201t provided
near the back edge of the capsule-type medical device C26.
When this endoscope device S1 is orally inserted, the capsule-type
medical device C26 is set in a condition anchored to the tip of the
endoscope 207 with the balloon 202K in a contracted state (in a
state in which the balloon 202K is substantially in close contact
with the outer circumference of the capsule main body 201E), as
shown in FIG. 43A, and the capsule-type medical device C26 and
endoscope 207 are inserted into the living body cavity in an
integrated manner. Furthermore, the capsule-type medical device C26
is caused to arrive at the position that is the target of
examination, such as the small intestine I, for example.
In this state, fluid is supplied to the inside of the balloon 202K
via the tube 206, the balloon 202K that has expanded substantially
around its entire circumference makes contact with the inner wall
of the small intestine I, and the tube 206 is removed and extracted
from the injection opening 217a while the capsule-type medical
device C26 is anchored substantially in the center of the inside of
the lumenal organ of the small intestine I. By removing the tube
206, the anchoring between the capsule-type medical device C26 and
the tube main body 206 is released, the tube main body 206 and
endoscope 207 are extracted to outside the living body and the
capsule-type medical device C26 alone remains in the small
intestine I.
The resistance created by the expanded balloon 202K and the inner
wall of the small intestine I controls the rotating and inclination
of the capsule-type medical device C26, and after the capsule-type
medical device C26 is left behind in the small intestine, the
position of the photographing element unit 212a positioned roughly
in the center of the lumenal organ is maintained even during motion
caused by peristaltic movement.
FIGS. 44A and 44B show the post-release situation of the
capsule-type medical device C26. FIG. 44A shows the state wherein
the axis of the capsule-type medical device C26 is maintained along
the center of the lumen, this being the state in which the
photographing element unit 212a takes photographs with the field of
view being the forward side of the lumen. In addition, FIG. 44B
shows a state in which the back of the capsule-type medical device
C26 shown in FIG. 44A has dropped to the bottom side of the lumen
so that the axis of the capsule-type medical device C26 is inclined
from the center of the lumen. Even in this state, it is possible to
take images using the photographing element unit 212a, with the
field of view being the forward side of the lumen.
When the balloon 202K is expanded, the pair of electrodes 203 on
the outer surface of the balloon 202K makes contact with the inner
wall of a digestive organ such as the small intestine I. In this
state, peristaltic movement can be promoted or local contraction of
the digestive organ can be caused through electric stimulus by
causing an electric current to flow intermittently from the battery
205 to the electrodes 203. As a result, through the activated
peristaltic movement or local contractions, the capsule-type
medical device C26 can be propelled more rapidly than under normal
conditions. In addition, the wires inside the balloon 202K are
flexible, and consequently the wires 204 inside the balloon 200K
can be freely deformed so that the occurrence of problems such as
breaking of the wires 204 can be prevented when the balloon is
expanded and contracted.
Riding the active peristaltic movement of the small intestine I or
the action of contractions of the small intestine I caused by the
electric stimulus, the balloon 202K is carried to the large
intestine while having the entire circumference as the field of
vision, and after also observing the large intestine arrives at the
anus. When the balloon 202K has difficulty passing to the outside
of the anus, a needle for creating a hole in the balloon 202K can
pierce the balloon from outside the anus.
The position where the balloon 202K of the capsule-type medical
device C26 is expanded need not be the small intestine I, but may
be the stomach or duodenum, and at this time a regular upper
digestive tract endoscope is used. In addition, in place of an
endoscope having an observation device, a simple guide tube
endoscope (guide member) having a curving function may be used.
In this endoscope device S1, it is possible to make the composition
of the capsule-type medical device C26 simple without making it
larger, and it is possible to expand the balloon 202K inside the
living body cavity through a simple method. In addition, it is
possible to leave only the capsule-type medical device C26 in the
living body cavity (inside the lumenal organ) after expansion of
the balloon so as to accomplish good observation and study.
In the above-shown third and fourth embodiments, the composition
shown is one in which at least one pair of bipolar electrodes is
attached to the flexible expansion unit, but this is intended to be
illustrative and not limiting, for it would also be fine to attach
at least one electrode, in other words, only one of the electrodes
that constitutes the pair, to the elastic expansion unit. In this
case, the other electrode in the pair may be attached directly to
the capsule main body and the spacing between electrodes may be
variable.
A fifth embodiment of the present invention will be shown with
reference to FIGS. 45A and 45B. In this embodiment, constituent
elements in common with the constituent elements in the above-shown
first or fourth embodiment are labeled with the same reference
numbers and detailed explanation of such is omitted.
In the flexible endoscope (device main body) 207S of the endoscope
device (capsule-type medical device) S2 of the present embodiment,
a balloon 202L similar to the above-shown balloon 202, electrodes
203 and flexible wires 204 are attached.
As shown in FIG. 45A, the flexible endoscope 207S has a hard member
275 provided at the tip of a flexible member 276S, and a connector
unit 278 on the base end. In the hard member 275, an object lens
275a, an illumination lens 275b and a channel 275c are provided, as
shown in FIG. 45B. In addition, the connector unit 278 is
positioned outside the living body, and is removably connected to
the connector unit 218 of the below-shown external device 310.
The balloon 202L is anchored on the back side of the hard member
275 in the endoscope 207S. A reference number 220e in the drawings
designates an endoscope 207S and a balloon 202L. At least one pair
of bipolar electrodes 203 is attached on the back side surface of
this balloon 202L. The electrodes and connector unit 278 are
connected by the flexible wires 204.
In addition, an injection and expulsion opening 277 is formed in
the flexible member 276 positioned on the inside of the balloon
202L in order to inject a fluid such as air or water into the
balloon 202L and expel the fluid from the inside of the balloon
202L. This injection and expulsion opening 277 are connected to the
connector unit 278, so that fluid from the below-shown external
device 310 can be injected and expelled.
The external device 310 is provided with a power source 311, a
limiter 311L, a light source device 312, a fluid injection and
expulsion device (expansion device) 313, a video processor 314, a
monitor 315 and a connector unit 318. If the connector unit 278 is
connected to the connector unit 318, illuminating light from the
light source device 312 can be conveyed to the illumination lens
276b, and the image from the object lens 275a can be conveyed to
the video processor 314 and stored in memory or displayed on the
monitor 315. In addition, the power source 311 and power source 203
are mechanically and electrically connected via the wires 204, and
electric current for causing an electric stimulus can be directed
from the power source 311 to the electrodes 203 via the wires 204.
Furthermore, the fluid injection and expulsion device 113 is
connected to the injection and expulsion opening, so that injection
of fluid into the balloon 202L or expulsion of fluid from the
balloon 202L can be accomplished.
In FIG. 45A, the endoscope device S2 is shown in the state in which
it is inserted into the large intestine R from the anus. When this
endoscope device S2 is inserted, the balloon 202L is in a
contracted state (a state in which the balloon 202L is essentially
in close contact with the outside surface of the flexible unit
276). Furthermore, after insertion, the balloon 202L is expanded
through the action of the fluid insertion and expulsion device 113,
and the power source 311 is caused to operate so that a square wave
electric current flows in pulses to the electrodes 203, an electric
stimulus is applied to the inner wall of the large intestine R and
the endoscope device S2 is propelled. When the device has arrived
at the target position, the electric stimulus is stopped or after
the electric stimulus is stopped the balloon 202L is caused to
expand so as to remain at the position, and observation and studies
of the large intestine R are conducted. At this time, electric
current of a set value or higher is prevented from flowing to the
electrodes 203 by the limiter 311L.
Furthermore, after observation and studies are concluded, when the
endoscope device S2 is removed from the large intestine R, the
balloon 202L is caused to contract the same as at insertion so that
it passes easily from the anus.
In this endoscope device S2, the flexible endoscope has a
composition that includes a balloon, electrodes and flexible wires,
and because of this, it is possible to add to a regular flexible
endoscope a function that applies a stable electric stimulus to
contractible tissue. In addition, because the power source that
applies the electric stimulus and the expansion device of the
balloon are provided externally, the composition of the part of the
endoscope device that is inserted into the living body cavity can
be made simple.
A sixth embodiment of the present invention will be shown with
reference to FIGS. 46A through 50C. In this embodiment, constituent
elements in common with the constituent elements in the above-shown
third, fourth and fifth embodiments are labeled with the same
reference numbers and detailed explanation of such is omitted.
As shown in FIGS. 46A and 46B, a balloon unit 208 is attached to
the capsule main body (device main body) 201G of the endoscope
device (capsule-type medical device) S3.
The capsule main body 201G is a general-purpose capsule-like
endoscope having a composition with the square wave generating
circuit 213a and expansion and contraction mechanism unit 16
omitted from the capsule main body 201 in the above-shown
capsule-type medical device C14. The casing of the capsule main
body 201G can be separated into a front casing 211x and a rear
casing 211y, as shown in FIG. 46B, and inside this a button-like
battery 205 can be mounted. A groove 211h is formed in the outside
circumference of this casing (the rear casing 211y in FIG.
46B).
The balloon unit 208 is provided with a flexible tube 281, a
mounting unit 282, a balloon (elastic expansion unit) 202M that is
the same as the above-shown balloon 202, at least one pair of
electrodes 203 and flexible wires 204.
The base end of the tube 281 is connected to an unrepresented
external device, and the mounting unit 282 is attached in an
integrated manner to the tip thereof. The mounting unit 282 can be
removably attached in an integrated manner to the capsule main body
201G and on it a band unit 282b is provided that is made from an
elastic body that interlocks with the groove unit 211h of the
capsule main body 201G. The balloon 202M is anchored to the tube
281 to the rear side of this mounting unit 282. Reference number
220g in the drawings designates an anchoring unit that anchors the
tube 281 and the balloon 202M. At least one pair of bipolar
electrodes 203 is removably attached to the back side surface of
the balloon 202M. To these electrodes 203 are attached flexible
wires 204 that pass through the inside of the tube 281 and whose
base end is connected to the external device. That is to say, the
electrodes 203 and the external device are mechanically and
electrically connected via the flexible wires 204, and electric
current from the external device can flow to the electrodes 203 via
the wires 204.
In addition, in the tube 281 positioned on the inside of the
balloon 202M, an injection and expulsion opening 281h is formed for
injecting fluid into the balloon 202M and expelling fluid from the
balloon 202M. This injection and expulsion opening 281h connects to
an external device so that fluid can be injected into and expelled
from the external device.
FIG. 47A shows the state when the endoscope device S3 is inserted
into the large intestine R from the anus P. When this endoscope
device S3 is inserted, the balloon 202M is in a contracted state
(the balloon 202M is in a state substantially in close contact with
the outer surface of the tube 281). After insertion, the external
device is operated and, as shown in FIGS. 47B and 47C, the balloon
202M is caused to expand, the power source 311 is caused to operate
and a square wave electric current flows in pulses to the
electrodes 203, an electric stimulus is applied to the inner wall
of the large intestine R, and the endoscope device S3 is caused to
propel. When the device has arrived at the target position, the
electric stimulus is stopped or after the electric stimulus is
stopped the balloon 202M is caused to expand so as to remain at the
position, and observation and studies of the large intestine R are
conducted.
Furthermore, after observation and studies are concluded, when the
endoscope device S3 is removed from the large intestine R, the
balloon 202M is caused to contract the same as at insertion so that
it passes easily from the anus.
As shown in FIG. 48, if the endoscope device S3 is used in
combination with a flexible endo scope 207W, observation and
studying of the deepest areas of the large intestine R, that is to
say the appendix A and the ileocecum valve V can be easily
accomplished. Specifically, by inserting the endoscope device S3
first and using the tube 281 as a guide wire for the flexible
endoscope 207W, insertion of the endoscope into the large intestine
R, which requires skill in the insertion operation, can be easily
accomplished.
In addition, it is preferable for the flexible endoscope 207W to be
a two-channel type as shown in FIG. 48. If this endoscope is a
two-channel type, the tube 281 of the endoscope device S3 can be
passed through the first channel Ch1 and forceps F or the like can
be passed through the second channel Ch2. That is to say, it is
possible to accomplish observation and studies though the endoscope
S3 and treatment of pathological changes (such as polyps) by means
of the forceps F all at once.
A balloon unit 209 is attached to the capsule main body (device
main body) 201H of an endoscope device (capsule-type medical
device) S4, as shown in FIGS. 49A and 49B.
The capsule main body 201H has observation windows 211d1 and 211d2
formed on both front and back sides in the above-shown capsule main
body 201, and inside these observation windows 211d1 and 211d2,
living in-vivo information acquisition device (omitted from the
drawings here) consisting of the above-shown photographing unit 212
and various sensors are provided. The operation of the living
in-vivo information acquisition device between front and back is
appropriately controlled by the various control units 213 (omitted
from the drawings here). In addition, one groove unit 211h is
formed on each of the front and back sides in this capsule main
body 201H.
The balloon unit 209 is provided with a balloon (elastic expansion
unit) 202N similar to the above-shown balloon 202, a mounting band
unit 291, at least one pair of electrodes 203, flexible wires 204,
a tube 292 and an wire jacket 293, as shown in FIGS. 49A, 49B and
50A.
On both the front and back edges of the balloon 202N, mounting band
units 291b composed of elastic bodies that respectively interlock
with the groove units 211h of the capsule main body 201H are each
provided in an integrated manner. Through these mounting band units
291b, the balloon 202N is removably attached in an integrated
manner to the capsule main body 201H. The flexible tube 292 is
attached to the back side of this balloon 202N. A connector 292c
that connects to the external device is formed on the base end of
this tube 292. Here, a syringe (expansion device) 321 and two-way
valve (expansion device) 321v are shown as examples of the external
device. By operating the syringe 321 and two-way valve 321v, fluid
can be injected into the balloon 202N and fluid can be expelled
from the balloon 202N.
In addition, at least one pair of bipolar electrodes 203 is
attached to the front side surface of the balloon 202N. To these
electrodes 203 are attached flexible wires 204 that pass through
the flexible wire jacket 293 attached to the back side of the
balloon 202N and are connected to the base-side connector 293c. The
connector 293c is connected to a connector 322c provided on the
power supply device 322 in one example of the external device. That
is to say, if the connector 293c and connector 322c are linked, the
electrodes 203 and power supply device 322 are mechanically and
electrically connected by the flexible wires 204, and electric
current from the power supply device 322 can flow to the electrodes
203 via the wires 204.
FIG. 50B shows the state when the endoscope device S4 is inserted
into the large intestine R from the anus P. When this endoscope
device S4 is inserted, the balloon 202N is in a contracted state
(the balloon 202N is in a state substantially in close contact with
the outer surface of the capsule main body 201H). Furthermore, the
device is inserted into the large intestine R with the back side of
the capsule main body 201H facing forward, that is to say with the
observation window 211d2 positioned on the front side. When the
device is inserted in this manner, the electrodes 203 are
positioned at the back side (the anus P side) so that the device
can be propelled toward the deep parts of the large intestine R.
After the device has been inserted, the balloon 202N is caused to
expand by operating the syringe 321 and the two-way valve 321v, and
the endoscope device S4 is caused to propel by the power supply
device 322 being caused to act so that square wave electric current
flows in pulses to the electrodes and an electric stimulus is
applied to the inner wall of the large intestine R. Furthermore,
when the target position is reached, the electric stimulus is
stopped and the device remains at the position, and observation and
studies of the large intestine R are accomplished from the front
and back observation windows 211d1 and 211d2.
Furthermore, when the endoscope device S4 is removed from the large
intestine R after observation and studies are complete, the tube
292 and wire jacket 293 are pulled from outside the living body and
the capsule main body 201H faces in the opposite direction to what
it has to that point. In this manner, the electrodes 203 are
positioned at the front side (the side toward the deep parts of the
large intestine R) and can cause the device to propel toward the
anus P.
When the capsule main body 201H approaches the anus P, the balloon
202N is caused to contract the same as at the time of insertion, so
that the device can be easily extracted from the anus P.
These endoscope devices S3 and S4 have a composition with a
balloon, electrodes and flexible wires attached to the capsule main
body as a capsule-type medical device and because of this it is
possible to add to a regular capsule-type endoscope a function that
applies a stable electric stimulus to contractible tissue. In
addition, because the power source that applies the electric
stimulus and the expansion device of the balloon are provided
externally, the composition of the part of the endoscope device
that is inserted into the living body cavity can be made
simple.
In the above-shown fifth and sixth embodiments, the composition is
such that a pair or a plurality of pairs of electrodes are attached
to the balloon, but this is intended to be illustrative and not
limiting, for at least one electrode, that is to say only one out
of the electrodes that constitute the pair, may be attached to the
balloon. In this case, the other of the electrodes that constitute
the pair is attached to the surface of the subject's body, giving a
monopolar electrode composition with electric current flowing to
both electrodes from the external device.
In the capsule-type medical device of the present invention, an
wire anchoring device may also be provided that anchors the
above-shown flexible wires inside the above-shown groove and
dissolves inside the living body.
Because the flexible wires are anchored in the groove by an wire
anchoring device of this type, the flexible wires and electrodes do
not become an obstruction when the capsule-type medical device is
introduced into the living body, for example when the device is
swallowed, so that introduction into the living body can be made
easier. Furthermore, after the device is introduced, the wire
anchoring device is dissolved for example by the stomach acid, and
because of this the anchoring of the flexible wires is released
inside the living body so that the spacing between electrodes can
vary.
In the capsule-type medical device of the present invention, a
spring may be provided between the above-shown outer shell unit and
above-shown casing that pushes the above-shown outer shell unit
toward the outside.
If a spring is used in this manner, it is possible to move the
outer shell unit toward the outside by means of a predetermined
energizing force, so that the spacing between electrodes can vary
and differences in diameter of the lumen organ inside the living
body can be accurately absorbed.
In the capsule-type medical device of the present invention, a
water-absorbing gel that expands when absorbing water may be
interposed between the above-shown outer shell unit and the
above-shown casing.
If a water-absorbing gel is used in this manner, it is possible to
cause the outer shell unit to move to the outside when water is
absorbed after the device has been introduced into the living body,
and consequently, it is possible to vary the distance between
electrodes accurately with a simple composition.
In the capsule-type medical device of the present invention, the
above-shown electrodes may be hemispherical electrodes that form a
hemisphere protruding from the outer surface of the above-shown
outer shell unit.
If the electrodes have this kind of hemispherical shape, it is
possible to make it easy to contact the body tissue and because
there are no corners it is possible to control worriers that the
progress of the capsule-type medical device will be blocked.
In the capsule-type medical device of the present invention, the
above-shown electrodes may be cylindrically shaped electrodes that
form cylinders protruding from the outer surface of the above-shown
outer shell unit.
If the electrodes have this kind of cylindrical shape, it is
possible to expand the area of contact with the body tissue, and
consequently it is possible to apply an electric stimulus
accurately even to body tissue such as mucous membranes, for
example.
In the capsule-type medical device of the present invention, the
above-shown electrodes may be embedded electrodes embedded in the
above-shown outer shell unit so as to have substantially the same
surface as the outer surface of the above-shown outer shell
unit.
If the electrodes are embedded in this manner, the device can be
made smoothly continuous without the electrodes protruding from the
outer surface of the outer shell unit, and consequently it is
possible to virtually eliminate the worry that the progress of the
capsule-type medical device will be blocked.
In the capsule-type medical device of the present invention, the
above-shown electrodes may be removable from the above-shown
elastic expansion unit.
In the capsule-type medical device of the present invention, the
above-shown expansion unit may be a balloon that expands when a
fluid is injected inside.
In the capsule-type medical device of the present invention, the
above-shown expansion unit may be flexible rubber that can be
contracted by being folded.
In the capsule-type medical device of the present invention, the
above-shown electrodes may be conductive rubber.
In the capsule-type medical device of the present invention, the
above-shown device main body may be a capsule-like endoscope.
In the capsule-type medical device of the present invention, the
above-shown device main body may be a flexible endoscope.
In the capsule-type medical device of the present invention, the
above-shown elastic expansion unit may have a shape that can form
spaces passing through to the above-shown body tissue from front to
back across the unit.
In the capsule-type medical device of the present invention, the
above-shown expansion device may be a flexible tube that connects
to a fluid injection and expulsion device outside the living
body.
In the capsule-type medical device of the present invention, the
above-shown tube may be removable after expansion of the
above-shown balloon.
In the capsule-type medical device of the present invention, the
above-shown expansion device may be a fluid release mechanism that
discharges into the above-shown balloon a pressurized gas or
foaming agent inside the above-shown device main body via operation
from outside the living body.
In the capsule-type medical device of the present invention, the
outer diameter of the above-shown elastic expansion unit may be set
at roughly 15 mm when contracted and roughly 40 mm when expanded to
the maximum.
In the capsule-type medical device of the present invention, the
above-shown electrodes need not be a pair.
Above, the preferred embodiments of the present invention have been
shown, but these are intended to be illustrative and not limiting.
Additions to, omissions from, changes to and other alterations are
possible without deviating from the main point of the present
invention. The present invention is only limited by the scope of
the attached claims, without being limited by the foregoing
explanations. In addition, the present invention includes devices
that appropriately incorporate the above-shown various embodiments
and variations thereof.
INDUSTRIAL APPLICABILITY
The capsule-type medical device of the present invention is a
capsule-type medical device that is introduced into a living body
and detects living in-vivo information, and this device is equipped
with: a casing having a capsule shape; a living in-vivo information
acquisition device provided in the casing that acquires the living
in-vivo information; a communications device that wirelessly
transmits to outside the living body the living in-vivo information
acquired by the living in-vivo information acquisition device; at
least one pair of first electrodes that are provided at one of the
edges of the casing and apply an electric stimulus to body tissue
inside the living body; a first electric current control device
that controls the electric current flowing to the first electrodes;
and an interelectrode distance variation device that causes the
distance between the first electrodes to change. With the
capsule-like medical device of the present invention, it is
possible to greatly change the distance between electrodes inside a
living body, and consequently it is possible to cause the
electrodes to accurately contact body tissue even in organs with
large lumenal organ. Accordingly, it is possible to cause the
capsule-type medical device to propel in a stable manner inside the
living body.
* * * * *